SUMMARY

This summary highlights selected information contained in this document and may not contain all of the information that is important to you. McDermott and CB&I urge you to read this entire document carefully, including its annexes and the other documents referred to herein. A copy of the Business Combination Agreement, as amended, is attached as Annex A-1 and Annex A-2 to this document and is incorporated by reference herein. See “Where You Can Find More Information” beginning on page 219 of this document. McDermott and CB&I have included in this summary references to other portions of this document to direct you to a more complete description of the topics presented, which you should review carefully in their entirety.

Information About the Companies

McDermott International, Inc. (see page 181)

McDermott International, Inc., which we refer to as “McDermott,” a corporation incorporated under the laws of the Republic of Panama in 1959, is a leading provider of integrated engineering, procurement, construction and installation, front-end engineering and design and module fabrication services for upstream field developments worldwide.

McDermott’s common stock, par value $1.00 per share (“McDermott Common Stock”) is listed on the New York Stock Exchange (“NYSE”) under the trading symbol “MDR.” McDermott’s principal executive offices are located at 4424 West Sam Houston Parkway North, Houston, Texas 77041, and its telephone number at that location is (281) 870-5000.

Chicago Bridge & Iron Company N.V. (see page 182)

Founded in 1889, Chicago Bridge & Iron Company N.V., which we refer to as “CB&I,” provides a wide range of services, including conceptual design, technology, engineering, procurement, fabrication, modularization, construction and services to customers in the energy infrastructure market throughout the world.

CB&I’s common stock, par value EUR 0.01 per share (“CB&I Common Stock”) is listed on the NYSE under the trading symbol “CBI.” CB&I’s principal executive offices are located at Prinses Beatrixlaan 35, 2595 AK, The Hague, The Netherlands and its telephone number at that location is 011-31-70-373-2010. CB&I’s administrative headquarters are located at One CB&I Plaza, 2103 Research Forest Drive, The Woodlands, TX 77380, USA and its telephone number at that location is (832) 513-1000.

McDermott Technology, B.V.

McDermott Technology, B.V., which we refer to as “McDermott Bidco,” is a company incorporated under the laws of the Netherlands and a direct wholly owned subsidiary of McDermott that was formed on December 14, 2017, solely for the purpose of effecting the Combination. To date, McDermott Bidco has not conducted any material activities other than those incidental to its formation and the matters contemplated by the Business Combination Agreement, dated as of December 18, 2017, by and among McDermott, CB&I and the other parties thereto (as it may be amended or supplemented from time to time, the “Business Combination Agreement”).

Comet I B.V. (see page 182)

Comet I B.V., which we refer to as “CB&I Newco,” is a company incorporated under the laws of the Netherlands and a direct wholly owned subsidiary of CB&I that was formed on December 12, 2017, solely for the purpose of effecting the Combination. To date, CB&I Newco has not conducted any material activities other than those incidental to its formation and the matters contemplated by the Business Combination Agreement. On December 13, 2017, CB&I Newco formed Comet II B.V. to facilitate the Combination.

Comet II B.V.

Comet II B.V., which we refer to as “CB&I Newco Sub,” is a company incorporated under the laws of the Netherlands and a direct wholly owned subsidiary of CB&I Newco that was formed on December 13, 2017, solely for the purpose of effecting the Combination. To date, CB&I Newco Sub has not conducted any material activities other than those incidental to its formation and the matters contemplated by the Business Combination Agreement.

The Combination (see page 55)

Pursuant to the Business Combination Agreement, McDermott and CB&I have agreed to combine their businesses through a series of transactions (and subject to the terms and conditions of the Business Combination Agreement) that we refer to as the “Core Transactions,” preceded by the Exchange Offer (the Core Transactions, together with the Exchange Offer, the “Combination”). The Business Combination Agreement is more fully described in the section “The Business Combination Agreement” and a copy of the Business Combination Agreement, as amended, is attached as Annex A-1 and Annex A-2 to this document. You should read the entire Business Combination Agreement carefully in its entirety before making any decisions regarding the Combination because it is the legal document that governs the relationship between McDermott and CB&I with respect to the Combination.

On the terms and subject to the conditions of the Business Combination Agreement, the Combination will occur as follows:

The “Core Transactions” consist of the CB&I Technology Acquisition, the Merger, the Share Sale and the Liquidation. The “Combination” consists of the Exchange Offer and the Core Transactions. Each step of the Combination is intended to be completed substantially concurrently, provided that the Liquidation Distribution will occur on the date of consummation of the Combination (the “Closing Date”) or as soon as practicable thereafter.

Below is a description of each of these steps in the Combination.

Step 1—CB&I Technology Acquisition (see page 127)

In the CB&I Technology Acquisition, McDermott Technology (2), B.V. and McDermott Technology (3), B.V. intend to acquire, for cash, no later than immediately prior to the Exchange Offer Effective Time, certain subsidiaries of CB&I (as specified in the Business Combination Agreement), and each of McDermott Technology (Americas), Inc. and McDermott Technology (US), Inc. intends to acquire for cash 50% of certain subsidiaries of CB&I (as specified in the Business Combination Agreement). Together, these acquired entities operate CB&I’s technology business (primarily consisting of CB&I’s former Technology reportable segment and its “Engineered Products Operations,” representing a portion of its Fabrication Services reportable segment). The cash proceeds to be paid by such McDermott entities pursuant to the CB&I Technology Acquisition in the aggregate amount of $2.65 billion will be used to fund the repayment of all the outstanding funded indebtedness of CB&I and its subsidiaries and to provide for future working capital needs of those entities (or their successors).

Step 2—The Exchange Offer (see page 129)

In the “Exchange Offer,” CB&I shareholders will be offered to exchange each of their issued and outstanding shares of CB&I Common Stock for 2.47221 shares of McDermott Common Stock or, if the McDermott Reverse Stock Split has occurred prior to the Exchange Offer Effective Time, 0.82407 shares of McDermott Common Stock.

If all of the shares of CB&I Common Stock outstanding as of March 26, 2018 were exchanged in the Exchange Offer, the aggregate number of shares of McDermott Common Stock issued to the CB&I shareholders will equal approximately 47% of the shares of McDermott Common Stock outstanding at the completion of the Combination.

Commencement and Expiration of the Exchange Offer

McDermott Bidco will commence the Exchange Offer promptly. The Exchange Offer will expire at 12:01 a.m., Eastern time, which we sometimes refer to as New York City time, on May 10, 2018, subject to extension as described below (such time, or such later time to which the Exchange Offer has been so extended, is referred to as the “Exchange Offer Expiration Time”).

Conditions to the Exchange Offer as Part of the Combination

The Exchange Offer, as part of the Combination, is subject to the satisfaction or, where permissible, waiver of certain conditions described in the section “The Business Combination Agreement—The Exchange Offer—Conditions to the Combination.”

Acceptance of Shares of CB&I Common Stock in the Exchange Offer

The obligation of McDermott Bidco to accept for exchange, and the obligation of McDermott to issue shares of McDermott Common Stock to McDermott Bidco to offer in exchange for, any shares of CB&I Common Stock validly tendered and not properly withdrawn pursuant to the Exchange Offer will be subject only to the satisfaction (or waiver) of the closing conditions set forth above under the heading “—Conditions to the Exchange Offer as Part of the Combination.” If McDermott Bidco accepts shares of CB&I Common Stock in the Exchange Offer in accordance with the terms of the Business Combination Agreement, then the McDermott entities that are parties to the Business Combination Agreement (the “McDermott Parties”) and the CB&I entities that are parties to the Business Combination Agreement (the “CB&I Parties”) will complete the actions contemplated by the Business Combination Agreement with respect to the Core Transactions on the Closing Date, provided that the Liquidation Distribution will occur on the Closing Date or as soon as practicable thereafter.

Extension of the Exchange Offer

McDermott Bidco may extend the Exchange Offer to such other date and time as may be agreed in writing by McDermott and CB&I, and McDermott Bidco will extend the Exchange Offer for any minimum period as may be required by the SEC (including, without limitation, for any five-day extension period or longer period required under Rule 14d-4 or Rule 14e-1 under the Exchange Act) or the NYSE. McDermott Bidco will also extend the Exchange Offer on one or more occasions if, at the then-scheduled Exchange Offer Expiration Time, any condition to the Exchange Offer has not been satisfied or waived. McDermott Bidco is not required to extend the Exchange Offer beyond the Termination Date (as defined herein).

Step 3—The Merger (see page 130)

Promptly following the Exchange Offer Effective Time, CB&I, as the disappearing company, will merge with and into CB&I Newco Sub in a legal triangular merger (juridische driehoeksfusie), resulting in each holder of outstanding shares of CB&I Common Stock holding a number of shares in the capital of CB&I Newco equal to the number of shares of CB&I Common Stock held by such holder of shares of CB&I Common Stock (the “Merger Consideration”) immediately prior to the completion of the Merger. The Merger is discussed in more detail in the section “The Business Combination Agreement—The Merger.”

CB&I, CB&I Newco and CB&I Newco Sub will effectuate the Merger promptly following the Exchange Offer Effective Time, in order to ensure that the Merger becomes effective at midnight Amsterdam time (being either 6:00 p.m., New York City time, or 7:00 p.m., New York City time), on the date the Exchange Offer Effective Time occurs. We refer to the effective time of the Merger as the “Merger Effective Time.”

Step 4—The Share Sale (see page 131)

Immediately following the Merger Effective Time, CB&I Newco will transfer all of the issued and outstanding shares in the capital of CB&I Newco Sub (the surviving entity in the Merger) to McDermott Bidco in exchange for an exchangeable note issued by McDermott Bidco (the “Exchangeable Note”) (which will be mandatorily exchangeable for shares of McDermott Common Stock other than to the extent any portion of the Exchangeable

Note is distributed to McDermott Bidco or any other controlled affiliate of McDermott). In connection therewith, immediately following the Merger Effective Time, McDermott Bidco, CB&I Newco and CB&I Newco Sub will enter into a notarial deed of transfer of shares pursuant to which all issued and outstanding shares in the capital of CB&I Newco Sub will be transferred by CB&I Newco to McDermott Bidco or its designated nominee at such time and such transfer will be acknowledged by CB&I Newco Sub. We refer to the effective time of such execution and acknowledgement as the “Share Sale Effective Time.”

Step 5—Pre-Liquidation Transactions (see page 131)

Exchangeable Note Split

Pursuant to the terms of the Exchangeable Note, immediately following the Share Sale Effective Time, the Exchangeable Note will automatically be split into two notes, one of which will be the “McDermott Component Note” and the other of which will be the “Legacy CB&I Component Note” (the “Exchangeable Note Split”). The McDermott Component Note will entitle the holder(s) thereof to receive a number of shares of McDermott Common Stock equal to the product of the Exchangeable Note principal amount multiplied by the percentage of outstanding shares of the common stock of CB&I Newco (“CB&I Newco Common Stock”) owned at such time by McDermott and its subsidiaries (other than CB&I Newco). The Legacy CB&I Component Note will entitle the holder(s) thereof to receive a number of shares of McDermott Common Stock equal to the product of the Exchangeable Note principal amount multiplied by the percentage of outstanding shares of CB&I Newco Common Stock owned at such time by persons that are not affiliates of McDermott (“CB&I Newco Public Shareholders”). As soon as McDermott or any of its subsidiaries (other than CB&I Newco) becomes the holder of the McDermott Component Note, the McDermott Component Note will immediately terminate and any rights thereunder will be extinguished and no longer due.

Deposit and Exchange

Immediately following the Exchangeable Note Split, CB&I Newco will deposit the Legacy CB&I Component Note with Computershare Trust Company, N.A., which is acting as the exchange agent in connection with the Exchange Offer, the Merger and the Liquidation (the “Exchange Agent”). Upon receipt by the Exchange Agent, the Legacy CB&I Component Note will automatically and mandatorily be exchanged into a number of shares of McDermott Common Stock equal to the product of the Exchange Offer Ratio and the number of shares of CB&I Newco owned at such time by the CB&I Newco Public Shareholders (the “Mandatory Exchange”). Prior to the execution of the Exchangeable Note, McDermott will have deposited with the Exchange Agent a number of shares of McDermott Common Stock sufficient to permit the completion of the Mandatory Exchange. The number of shares of McDermott Common Stock required to be issued in the Mandatory Exchange will be rounded up to the nearest whole share. Upon completion of the Mandatory Exchange, the Legacy CB&I Component Note will be deemed fully paid and the indebtedness represented by the Exchangeable Note will be deemed fully satisfied.

McDermott Common Stock Sale to Satisfy Dutch Dividend Withholding Tax Obligations

Pursuant to the terms of the Exchangeable Note, CB&I Newco will cause the Exchange Agent to sell (the “McDermott Common Stock Sale”), in one or more transactions for the benefit of the CB&I Newco Public Shareholders, shares of McDermott Common Stock that the CB&I Newco Public Shareholders would otherwise be entitled to receive in order to obtain sufficient net cash proceeds to satisfy the Dutch Dividend Withholding Tax in connection with the Liquidation Distribution (as defined herein). In the event that the cash proceeds obtained by the Exchange Agent in the McDermott Common Stock Sale exceed the required applicable withholding by more than a de minimis amount, those surplus cash proceeds will be distributed, net of applicable Dutch Dividend Withholding Tax, to the CB&I Newco Public Shareholders on a pro rata basis, along with any cash payable in lieu of fractional shares. McDermott will be entitled to retain any de minimis surplus cash proceeds.

Step 6—The Liquidation (see page 132)

As soon as practicable after the Share Sale Effective Time, CB&I Newco will be dissolved and subsequently liquidated, making one or more liquidating distributions such that each holder of shares of CB&I Common Stock not validly tendered in (or properly withdrawn from) the Exchange Offer will receive, as a liquidation distribution, shares of McDermott Common Stock for each such share (together, the “Liquidation Distribution”) as follows:

In connection with the Liquidation Distribution, the Exchange Agent will pay to the relevant Dutch tax authority the net cash proceeds from the McDermott Common Stock Sale in satisfaction of CB&I Newco’s obligation to remit Dutch Dividend Withholding Tax in respect of the Liquidation Distribution.

Non-tendering CB&I shareholders who receive shares of McDermott Common Stock pursuant to the Liquidation Distribution rather than the Exchange Offer generally will be subject to Dutch Dividend Withholding Tax. See “Material Tax Consequences of the Combination.”

Once the final Liquidation Distribution has occurred, CB&I Newco will cease to exist by operation of law.

The McDermott Special Meeting (see page 37)

Meeting (see page 37)

The McDermott Special Meeting is scheduled to be held on May 2, 2018, at 9:00 a.m., Central Daylight Saving Time, at the offices of Baker Botts L.L.P., 910 Louisiana, 32^nd floor, Houston, Texas. At the McDermott Special Meeting, McDermott stockholders will be asked to vote on:

The McDermott Reverse Stock Split Articles Amendment Resolution, the McDermott Authorized Capital Articles Amendment Resolution, McDermott Stock Issuance proposal and the McDermott Meeting Adjournment proposal are collectively referred to in this document as the “McDermott Stockholder Proposals.” The approvals of the McDermott Stock Issuance proposal and either the McDermott Reverse Stock Split Articles Amendment Resolution or the McDermott Authorized Capital Articles Amendment Resolution are collectively referred to in this document as the “McDermott Stockholder Approval.”

Record Date; Stockholders Entitled to Vote (see page 37)

The McDermott Board of Directors (the “McDermott Board”) established April 4, 2018 (the “McDermott Record Date”) as the record date for determining stockholders entitled to vote at the McDermott Special Meeting. This means that, if you were a stockholder of record (meaning that you were registered with McDermott’s transfer agent and registrar, Computershare Trust Company, N.A.) on the McDermott Record Date, you may vote your shares on the matters to be considered by McDermott’s stockholders at the McDermott Special Meeting. If your shares were held in street name on that date, the broker or other nominee that was the record holder of your shares has the authority to vote them at the McDermott Special Meeting. They have forwarded to you this joint proxy statement/prospectus seeking your instructions on how you want your shares voted.

As of the close of business on March 26, 2018, approximately 285.9 million shares of McDermott Common Stock were outstanding. Each outstanding share of McDermott Common Stock entitles its holder to one vote on each matter to be acted on at the meeting.

As of the close of business on March 26, 2018, the most recent practicable date prior to the date of this joint proxy statement/prospectus, less than 1.5% of the outstanding shares of McDermott Common Stock were held by McDermott directors and executive officers and their affiliates. McDermott’s directors and executive officers other than Stephen G. Hanks, who collectively own less than 1.5% of the outstanding shares of McDermott Common Stock, have informed McDermott that they intend, as of the date hereof, to vote their shares in favor of all of the proposals set forth above, although none has entered into any agreements obligating them to do so.

Required Vote (see page 38)

The affirmative vote of the holders of a majority of the shares of McDermott Common Stock outstanding and entitled to vote at the McDermott Special Meeting (meaning that, of the shares of McDermott Common Stock outstanding, excluding treasury shares, a majority must be voted “FOR” the proposal) is required to approve the McDermott Reverse Stock Split Articles Amendment Resolution and the McDermott Authorized Capital Articles Amendment Resolution. The affirmative vote of the holders of a majority of the votes cast on the matter by holders of shares of McDermott Common Stock present in person or represented by proxy at the McDermott Special Meeting (meaning the number of shares voted “FOR” the proposal must exceed the number of shares voted “AGAINST” the proposal plus abstentions) is required to approve the McDermott Stock Issuance proposal. The affirmative vote of the holders of a majority of the shares of McDermott Common Stock present in person or represented by proxy at the meeting, whether or not a quorum is present, is required to approve the McDermott Meeting Adjournment proposal.

Failures to vote, abstentions and broker non-votes will have the same effect as votes “AGAINST” the adoption of the McDermott Reverse Stock Split Articles Amendment Resolution and the adoption of the McDermott Authorized Capital Articles Amendment Resolution. Because failures to vote and broker non-votes are not actual votes cast (assuming that a quorum is present), they will have no effect on the outcome of the vote on the McDermott Stock Issuance proposal. However, under applicable rules of the NYSE, an abstention will have the same effect as a vote “AGAINST” the McDermott Stock Issuance proposal. Failures to vote by McDermott stockholders that attend the McDermott Special Meeting in person, abstentions and broker non-votes will have

the same effect as votes “AGAINST” the McDermott Meeting Adjournment proposal. Failures to vote by McDermott stockholders not attending the McDermott Special Meeting, in person or by proxy, will have no effect on the McDermott Meeting Adjournment proposal, whether or not a quorum is present.

The Combination cannot be completed unless the McDermott stockholders approve the McDermott Stock Issuance and either the McDermott Reverse Stock Split Amendment Resolution or the McDermott Authorized Capital Articles Amendment Resolution.

Recommendation of the McDermott Board (see page 37)

The McDermott Board has approved, and, by a vote of eight to one, recommends that you vote “FOR,” the McDermott Reverse Stock Split Articles Amendment Resolution, the McDermott Authorized Capital Articles Amendment Resolution, the McDermott Stock Issuance proposal and the McDermott Meeting Adjournment proposal. For McDermott’s reasons for these recommendations, see “The Combination—McDermott’s Reasons for the Combination; Recommendation of the McDermott Board.”

The CB&I Special General Meeting (see page 48)

Meeting (see page 48)

The CB&I Special General Meeting is scheduled to be held on May 2, 2018, at 3:00 p.m., Central European Time, at the InterContinental Amstel Amsterdam, Professor Tulpplein 1, 1018 GX Amsterdam. At the CB&I Special General Meeting, CB&I shareholders will be asked to vote on:

The Articles Amendment Resolution, the Merger Resolution, the Sale Resolutions, the Liquidation Resolutions, the Discharge Resolutions and the Compensation Resolution are collectively referred to in this document as the

“CB&I Shareholder Proposals.” The approvals of the Merger Resolution, the Sale Resolutions, the Liquidation Resolutions and the Discharge Resolutions are collectively referred to in this document as the “CB&I Shareholder Approval.”

Record Date; Shareholders Entitled to Vote (see page 48)

The CB&I Management Board established April 4, 2018 (the “CB&I Record Date”) as the record date for determining shareholders entitled to vote at the CB&I Special General Meeting. This means that if you were a shareholder of record (meaning that you were registered in the CB&I share register as referred to in section 2:85 of the Dutch Civil Code, part of which is kept by Computershare Trust Company, N.A. on behalf of CB&I (the “CB&I Share Register”)) on the CB&I Record Date, you may vote your shares on the matters to be considered by CB&I’s shareholders at the CB&I Special General Meeting, even if you already tendered your shares in the Exchange Offer. If your shares were held in street name on that date, the broker or other nominee that was the record holder of your shares has the authority to vote them at the CB&I Special General Meeting. They have forwarded to you this joint proxy statement/prospectus seeking your instructions on how you want your shares voted.

As of the close of business on March 26, 2018, approximately 102.5 million shares of CB&I Common Stock were outstanding. Each outstanding share of CB&I Common Stock entitles its holder to one vote on each matter to be acted on at the meeting.

As of the close of business on March 26, 2018, the most recent practicable date prior to the date of this joint proxy statement/prospectus, less than 1% of the outstanding shares of CB&I Common Stock were held by CB&I directors and executive officers and their affiliates. CB&I’s directors and executive officers have informed CB&I that they intend, as of the date hereof, to vote their shares in favor of all of the proposals set forth above, although none has entered into any agreements obligating them to do so.

Required Vote (see page 49)

The affirmative vote of a majority of the votes cast on the matter by holders of shares of CB&I Common Stock outstanding and entitled to vote at the CB&I Special General Meeting (meaning the number of shares voted “FOR” the proposal must exceed the number of shares voted “AGAINST” the proposal) is required to approve the Articles Amendment Resolution, the Sale Resolutions, the Liquidation Resolutions, the Discharge Resolutions and the Compensation Resolution at the CB&I Special General Meeting.

Assuming the Articles Amendment Resolution is adopted and implemented and so long as at least fifty percent (50%) of the issued and outstanding CB&I share capital is present at the CB&I Special General Meeting, in person or by proxy, the affirmative vote of at least a majority of the votes cast on the matter by holders of shares of CB&I Common Stock outstanding and entitled to vote at the CB&I Special General Meeting (meaning the number of shares voted “FOR” the proposal must exceed the number of shares voted “AGAINST” the proposal) is required to approve the Merger Resolution. If less than fifty percent (50%) of the issued and outstanding CB&I share capital is present at the CB&I Special General Meeting, in person or by proxy, the affirmative vote of two-thirds of the votes cast on the matter by holders of shares of CB&I Common Stock outstanding and entitled to vote at the CB&I Special General Meeting is required to approve the Merger Resolution.

However, if the Articles Amendment Resolution is not adopted at the CB&I Special General Meeting and there is a person that alone or together with a group (beneficially) holds more than fifteen percent (15%) of the issued and outstanding share capital of CB&I, the affirmative vote of at least eighty percent (80%) of the shares of CB&I Common Stock outstanding is required to approve the Merger Resolution. In such case, failures to vote by CB&I shareholders, whether or not they attend the CB&I Special General Meeting in person or by proxy,

abstentions and broker non-votes will have the same effect as votes “AGAINST” the adoption of the Merger Resolution.

The Combination cannot be completed unless the CB&I shareholders approve the Merger Resolution, the Sale Resolutions (to the extent required by applicable law), the Liquidation Resolutions and the Discharge Resolutions.

Recommendation of the CB&I Boards (see page 48)

The CB&I Boards have approved, and recommend that CB&I shareholders vote “FOR,” the Articles Amendment Resolution, the Merger Resolution, the Sale Resolutions, the Liquidation Resolutions, the Discharge Resolutions and the Compensation Resolution and accept the Exchange Offer. For CB&I’s reasons for these recommendations, see “The Combination—CB&I’s Reasons for the Combination; Recommendation of the CB&I Boards.”

Regulatory Approvals Related to the Combination (see page 124)

The Combination was subject to review by the Federal Trade Commission (the “FTC”) or the Antitrust Division of the U.S. Department of Justice, (the “Antitrust Division”), under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”). Under the HSR Act, McDermott and CB&I were required to make premerger notification filings and to await the expiration or early termination of the statutory waiting period prior to completing the Combination. On January 9, 2018, McDermott and CB&I each filed a Premerger Notification and Report Form with the Antitrust Division and the FTC pursuant to the HSR Act. On January 24, 2018, the Premerger Notification Office of the FTC advised McDermott and CB&I that early termination of the HSR Act waiting period had been granted.

The Russian Law on Protection of Competition requires an application for the consent of the Federal Antimonopoly Service of the Russian Federation in connection with the Combination. Once all required documents and information have been provided, there is a 30 calendar-day initial (phase I) investigation period. At its discretion, the Federal Antimonopoly Service may extend the review period by up to two months for an in-depth (phase II) investigation. McDermott filed an application for the consent of the Russian Federal Antimonopoly Service on February 5, 2018. On March 13, 2018, the Federal Antimonopoly Service of the Russian Federation provided clearance with respect to the Combination.

Under the terms of the Business Combination Agreement, McDermott and CB&I have agreed to use (and cause their respective subsidiaries to use) their reasonable best efforts to take, or cause to be taken, all actions, and do promptly, or cause to be done, and to assist and cooperate with the other parties in doing, all things necessary, proper or advisable under applicable laws to consummate and make effective the Combination and the other transactions contemplated by the Business Combination Agreement as promptly as practicable, including actions to obtain any necessary or advisable consents or approvals from third parties or governmental authorities. The McDermott Parties have also agreed to take all such action as may be necessary to resolve such objections, if any, that any governmental antitrust entity may assert under applicable antitrust law with respect to the transactions contemplated by the Business Combination Agreement, and to avoid or eliminate, and minimize the impact of, each impediment under antitrust law that may be asserted by any governmental antitrust entity with respect to the Combination to enable the Combination to occur as soon as reasonably possible, and in no event later than June 18, 2018, or a later date if the Termination Date (as defined below) has been extended. However, the Business Combination Agreement does not require any party to take any action with respect to any of the assets, businesses or product lines of McDermott, CB&I or any of their subsidiaries if such action, individually or in the aggregate, would reasonably be expected to have a Material Adverse Effect (as defined in the Business Combination Agreement) on the business, assets, results of operations or financial condition of McDermott, CB&I and their subsidiaries, taken as a whole. If requested by McDermott, CB&I will agree to take any action

necessary to facilitate the closing of the Combination, provided that the consummation of any divestiture or the effectiveness of any other remedy is conditioned on the consummation of the Combination. McDermott also has the obligation to defend any lawsuits or other legal proceedings, whether judicial or administrative, challenging the Combination or the consummation of the transactions contemplated by the Business Combination Agreement.

If the Combination has not occurred on or before the Termination Date due to the failure to obtain regulatory clearances, or if an order, decree or ruling in the United States, the Republic of Panama, Russia or the Netherlands permanently prohibits the Exchange Offer or any of the Core Transactions, the Business Combination Agreement may be terminated.

See “The Business Combination Agreement—Filings” for more information.

Post-Combination Governance and Management (see page 148)

At the closing of the Combination, the McDermott Board will have 11 members, including (1) six persons who are current members of the McDermott Board, two of which will be Gary Luquette, the Chairman of the McDermott Board, and David Dickson, the President and Chief Executive Officer of McDermott, and (2) five persons who are current members of the CB&I Supervisory Board. The current members of the McDermott Board designated as members of the McDermott Board following the Combination pursuant to the collaborative process contemplated by the Business Combination Agreement are, in addition to Mr. Luquette and Mr. Dickson, Philippe Barril, John F. Bookout, III, William H. Schumann, III and Mary L. Shafer-Malicki. The current members of the CB&I Supervisory Board designated as members of the McDermott Board following the Combination pursuant to such process are Forbes I. J. Alexander, L. Richard Flury, W. Craig Kissel, James H. Miller and Marsha C. Williams. Gary Luquette will continue as the Non-Executive Chair of the McDermott Board. David Dickson will continue as the President and Chief Executive Officer of McDermott and Stuart Spence will continue as the Executive Vice President and Chief Financial Officer of McDermott. Patrick Mullen, President and Chief Executive Officer of CB&I, will remain with the combined business for a transition period.

Appraisal Rights (see page 126)

Neither CB&I shareholders nor CB&I Newco shareholders are entitled under Dutch law or otherwise to appraisal or dissenters’ rights related to the CB&I Common Stock or CB&I Newco Common Stock in connection with the Exchange Offer or the Core Transactions.

McDermott stockholders are not entitled to appraisal or dissenters’ rights with respect to any of the matters to be considered and voted on at the McDermott Special Meeting.

Interests of Certain Persons in the Combination (see page 112)

McDermott International, Inc. (see page 112)

In considering the recommendation of the McDermott Board to vote in favor of the proposals on the agenda at the McDermott Special Meeting, McDermott stockholders should be aware that McDermott’s executive officers and directors have certain interests in the Combination that may be different from, in addition to, or in conflict with, the interests of the McDermott stockholders generally. These interests include, but are not limited to, the fact that such (i) executive officers are party to change-in-control agreements that provide severance benefits to such executive officers in the event their employment is terminated within one year following the closing of the Combination by McDermott for reasons other than cause or by the executive with good reason, as such terms are defined in the change-in-control agreements and (ii) such executive officers are eligible for the McDermott Recognition Program (as defined herein), providing retention awards based on continued service and achievement of specified cost reduction targets following the Combination (estimated total value for all executive

officers $5,030,800). Holders of shares of McDermott Common Stock should also be aware that certain of the executive officers and directors of McDermott will continue serving as executive officers and directors of McDermott immediately following the Combination. The McDermott Board was aware of these interests during the deliberation of the merits of the Business Combination Agreement and the transactions, as applicable, and in deciding to recommend that McDermott’s stockholders vote in favor of the proposals on the agenda at the McDermott Special Meeting. Please read “The Combination—Interests of Certain Persons in the Combination—McDermott International, Inc.”

Chicago Bridge & Iron Company N.V. (see page 117)

In considering the recommendation of the CB&I Boards to vote in favor of the proposals for resolution at the CB&I Special General Meeting, CB&I shareholders should be aware that CB&I’s executive officers and directors have certain interests in the Combination that may be different from, in addition to, or in conflict with, the interests of the CB&I shareholders generally. These interests include, but are not limited to, the fact that: (1) such executive officers and directors are party to certain agreements that provide for the vesting of equity awards (estimated total value for all officers and directors: $30.2 million) in connection with the Combination; (2) certain executive officers are eligible for severance benefits under their change-in-control agreements upon certain qualifying terminations of employment (estimated total value for all executive officers: $28.4 million); and (3) certain executive officers are eligible to receive a retention bonus in connection with the transaction (estimated total value for all executive officers: $805,834). The CB&I Supervisory Board and the CB&I Management Board were aware of these interests during the deliberation of the merits of the Business Combination Agreement and the transactions, and in deciding to recommend that CB&I’s shareholders vote in favor of the proposals for resolution at the CB&I Special General Meeting. Please read “The Combination—Interests of Certain Persons in the Combination—Chicago Bridge & Iron Company N.V.”

Treatment of Equity Awards (see page 133)

At the Merger Effective Time, all outstanding unexercised options to purchase shares of CB&I Common Stock (“CB&I Options”) will immediately vest and be converted into options to purchase shares of McDermott Common Stock with the duration and terms of such converted options to remain generally the same as the original CB&I Options. The number of shares of McDermott Common Stock subject to each converted option will be determined by multiplying the number of shares of CB&I Common Stock subject to the original CB&I Option by the Exchange Offer Ratio, rounded down to the nearest whole share. The option exercise price per share of McDermott Common Stock will be equal to the option exercise price per share of CB&I Common Stock under the original CB&I Option divided by the Exchange Offer Ratio, rounded up to the nearest whole cent.

At the Merger Effective Time, each outstanding award of performance shares relating to CB&I Common Stock (each, a “CB&I Performance Share Award”) will be canceled and converted into the right to receive cash, without interest and less applicable withholding taxes, in an amount equal to (1) the product of (a) the Exchange Offer Ratio, (b) the target number of shares of CB&I Common Stock subject to the CB&I Performance Share Award and (c) the closing price for a share of McDermott Common Stock on the business day immediately preceding the Closing Date plus (2) an amount equal to any dividend equivalents associated with the CB&I Performance Share Award at that time.

At the Merger Effective Time: (1) each outstanding restricted stock unit award granted by CB&I (“CB&I Restricted Stock Unit Award”) that is held by a non-employee member of the CB&I Supervisory Board (whether or not vested); (2) each vested CB&I Restricted Stock Unit Award held by a member of a specific group of executive officers of CB&I that has not been settled; (3) each CB&I Restricted Stock Unit Award that vests in accordance with its terms as a result of the Combination; and (4) each vested share of CB&I Common Stock deferred pursuant to any CB&I equity compensation plan, will, in each case, be converted into a right to receive (a) a number of shares of McDermott Common Stock equal to the product of (i) the number of shares of CB&I Common Stock subject to the original CB&I award and (ii) the Exchange Offer Ratio, rounded to the nearest

whole number of shares, plus (b) cash in an amount equal to any dividend equivalents associated with the CB&I Restricted Stock Unit Award at that time, subject to applicable withholding taxes.

At the Merger Effective Time, each other outstanding CB&I Restricted Stock Unit Award will be converted into a right to receive an award of restricted stock units that will be settled in McDermott Common Stock with substantially the same terms as the original CB&I award, including the vesting schedule and any conditions and restrictions on receipt. The number of shares of McDermott Common Stock subject to the converted restricted stock unit award will be determined by multiplying the number of shares of CB&I Common Stock subject to the original CB&I Restricted Stock Unit Award by the Exchange Offer Ratio, rounded to the nearest whole number of shares. The transactions contemplated by the Business Combination Agreement will not be considered a change in control for purposes of any award of CB&I Restricted Stock Unit granted on or after December 18, 2017.

Each converted equity award will, in accordance with its terms, be subject to further adjustment as appropriate to reflect any stock split, reclassification, recapitalization or other similar transaction of McDermott Common Stock subsequent to the Merger Effective Time.

At the Merger Effective Time, McDermott will assume the CB&I equity compensation plans and thereafter be entitled to grant equity or equity-based incentive awards with respect to McDermott Common Stock using the share reserves of the CB&I equity compensation plans as of the Merger Effective Time (including any shares of McDermott Common Stock returned to such share reserves as a result of the termination or forfeiture of an assumed award granted), except that: (1) shares covered by such awards will be shares of McDermott Common Stock; (2) all references in such CB&I stock plan to a number of shares will be deemed amended to refer instead to that number of shares of McDermott Common Stock (rounded down to the nearest whole share) as adjusted pursuant to the application of the Exchange Offer Ratio; and (3) the McDermott Board or a committee thereof will succeed to the authority and responsibility of the CB&I Boards or any applicable committee thereof with respect to the administration of such CB&I equity compensation plans.

CB&I’s Employee Stock Purchase Plan and Supervisory Board Stock Purchase Plan were suspended effective January 1, 2018, and such plans will be terminated effective as of, and contingent upon, the Merger Effective Time.

Financing for the Combination (see page 163)

In connection with the Business Combination Agreement, McDermott entered into or received commitment letters (including the exhibits and other attachments thereto, and together with any amendments, modifications or supplements thereto, the “Commitment Letters”) from certain financial institutions to provide debt financing for the Combination. Each of Barclays Bank PLC (“Barclays”), Crédit Agricole Corporate and Investment Bank (“CACIB”), Goldman Sachs Bank USA (“GS”), ABN AMRO Capital USA LLC (“ABN”), Royal Bank of Canada (“RBC”), The Bank of Tokyo-Mitsubishi UFJ, Ltd. (“BTMU”) and Standard Chartered Bank (“Standard Chartered”) are arrangers and/or agents for the debt financing and have provided commitments in respect thereof (Barclays, CACIB, GS, ABN, RBC, BTMU and Standard Chartered, together with the other financial institutions providing commitments for the debt financing are collectively referred to as the “Commitment Parties”). Pursuant to the Commitment Letters, McDermott expects to include the following activities as part of the debt financing:

Pursuant to the Commitment Letters, the Commitment Parties have committed to provide, subject to the terms and conditions set forth therein, (1) the Senior Credit Facilities and (2) senior unsecured bridge facilities in an aggregate principal amount of up to $1.5 billion, the availability of which will be subject to reduction upon the issuance of the Notes pursuant to the terms set forth in the Commitment Letters (the “Bridge Facilities” and, together with the Senior Credit Facilities, the “Facilities”).

Opinion of Financial Advisor to CB&I (see page 98)

CB&I retained Centerview Partners LLC (“Centerview”) as financial advisor to CB&I in connection with the Combination and the other transactions contemplated by the Business Combination Agreement. In connection with Centerview’s engagement, the CB&I Boards requested that Centerview evaluate the fairness, from a financial point of view, to the holders of outstanding shares of CB&I Common Stock (other than shares of CB&I Common Stock held by McDermott and its affiliates, which are collectively referred to as “Excluded Shares” throughout this section of the document and the summary of Centerview’s opinion below under the caption “Opinion of CB&I’s Financial Advisor”) of the Exchange Offer Ratio provided for pursuant to the Business Combination Agreement. On December 17, 2017, Centerview rendered to the CB&I Supervisory Board its oral opinion, which was subsequently confirmed by delivery of a written opinion to the CB&I Boards dated December 17, 2017 that, as of such date and based upon and subject to the assumptions made, procedures followed, matters considered, and qualifications and limitations upon the review undertaken by Centerview in preparing its opinion, the Exchange Offer Ratio provided for pursuant to the Business Combination Agreement was fair, from a financial point of view, to the holders of shares of CB&I common stock (other than Excluded Shares).

The full text of Centerview’s written opinion, dated December 17, 2017, which describes the assumptions made, procedures followed, matters considered, and qualifications and limitations upon the review undertaken by Centerview in preparing its opinion, is attached as Annex D and is incorporated herein by reference. Centerview’s financial advisory services and opinion were provided for the information and assistance of the CB&I Boards (in their capacity as directors and not in any other capacity) in connection with and for purposes of their consideration of the Combination and Centerview’s opinion addressed only the fairness, from a financial point of view, as of the date thereof, to the holders of shares of CB&I Common Stock (other than Excluded Shares) of the Exchange Offer Ratio provided for pursuant to the Business Combination Agreement. Centerview’s opinion did not address any other term or aspect of the Business Combination Agreement or the Combination and does not constitute a recommendation to any shareholder of CB&I or any other person as to how such shareholder or other person should vote with respect to the Combination or otherwise act with respect to the Combination or any other matter.

The full text of Centerview’s written opinion should be read carefully in its entirety for a description of the assumptions made, procedures followed, matters considered, and qualifications and limitations upon the review undertaken by Centerview in preparing its opinion.

Opinions of Financial Advisors to McDermott (see page 71)

Goldman Sachs & Co. LLC

Goldman Sachs & Co. LLC (“Goldman Sachs”) delivered its opinion to the McDermott Board that, as of December 18, 2017 and based upon and subject to the factors and assumptions set forth therein, the 2.47221, or,

if the McDermott Reverse Stock Split has occurred prior to the date on which the Exchange Offer Effective Time occurs, 0.82407, shares of McDermott Common Stock to be paid by McDermott Bidco for each share of CB&I Common Stock pursuant to the Business Combination Agreement was fair from a financial point of view to McDermott.

The full text of the written opinion of Goldman Sachs, dated December 18, 2017, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex B. Goldman Sachs provided advisory services and its opinion for the information and assistance of the McDermott Board in connection with its consideration of the Combination. The Goldman Sachs opinion is not a recommendation as to how any holder of shares of McDermott Common Stock should vote with respect to matters related to the Combination, or any other matter. Pursuant to an engagement letter between McDermott and Goldman Sachs, McDermott has agreed to pay Goldman Sachs a transaction fee of $16 million, all of which is contingent upon consummation of the Combination.

Greenhill & Co., LLC

Greenhill & Co., LLC (“Greenhill”) delivered its opinion to the McDermott Board that, as of December 18, 2017 and based upon and subject to the limitations and assumptions set forth therein, the 2.47221, or, if the McDermott Reverse Stock Split has occurred prior to the date on which the Exchange Offer Effective Time occurs, 0.82407, shares of McDermott Common Stock to be paid by McDermott Bidco for each share of CB&I Common Stock pursuant to the Business Combination Agreement was fair, from a financial point of view, to McDermott.

The full text of the written opinion of Greenhill, dated December 18, 2017, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex C. We encourage you to read Greenhill’s opinion, and the section “The Combination—Opinions of McDermott’s Financial Advisors—Greenhill & Co., LLC” carefully and in their entirety. Greenhill provided advisory services and its opinion solely for the information and assistance of the McDermott Board in connection with its consideration of the Combination. Greenhill’s opinion is not a recommendation as to how any holder of shares of McDermott Common Stock should vote with respect to matters related to the Combination, or any other matter. Pursuant to an engagement letter between McDermott and Greenhill, McDermott has agreed to pay Greenhill a transaction fee of $16 million, $3.2 million of which became payable upon delivery of Greenhill’s opinion to McDermott’s Board and the rest of which is contingent upon consummation of the Combination.

Conditions to the Combination (see page 148)

The respective obligations of each party to conduct the closing of the transactions contemplated by the Business Combination Agreement are subject to the fulfillment of the following conditions on or prior to the Closing Date:

Termination of the Business Combination Agreement (see page 149)

The Business Combination Agreement may be terminated at any time prior to the effective time of the CB&I Technology Acquisition:

Termination Fees (see page 151)

Termination of the Business Combination Agreement may require CB&I or McDermott to pay a cash termination fee of $60.0 million under certain circumstances. CB&I or McDermott will be required to pay the termination fee to the other party if:

Accounting Treatment (see page 112)

The Combination will be accounted for as a business combination in accordance with Accounting Standards Codification Topic ASC 805, Business Combination (“ASC 805”), with McDermott treated as the “acquirer” and CB&I treated as the “acquired” company for financial reporting purposes.

Listing of McDermott Shares; Delisting and Deregistration of CB&I Shares (see page 124)

As stated above, a condition to completion of the Combination is the approval for listing on the NYSE of all the shares of McDermott Common Stock to be issued in the Combination. McDermott has agreed to use its reasonable best efforts to obtain such approval from the NYSE. If the Exchange Offer and the Core Transactions are completed, CB&I intends to delist the CB&I Common Stock from the NYSE and deregister the CB&I Common Stock under the Securities Exchange Act of 1934, as amended.

Resales of McDermott Common Stock (see page 124)

The shares of McDermott Common Stock to be issued in the Combination will not be subject to any restrictions on transfer existing under the Securities Act, except for any shares issued to any CB&I shareholder who may be deemed to be an “affiliate” of McDermott after the completion of the Combination. This document does not cover resales of McDermott Common Stock by affiliates of McDermott or CB&I.

Litigation Relating to the Combination (see page 125)

In January, February and March 2018, five shareholders of CB&I filed separate lawsuits—four as putative class actions and one on an individual basis—in the United States District Court for the Southern District of Texas naming CB&I and the members of the CB&I Board of Directors as defendants and alleging violations of Sections 14(a) and 20(a) of the Exchange Act and Rule 14a-9 under the Exchange Act with respect to the registration statement to which this document forms a part. One of the putative class action lawsuits also names as defendants certain subsidiaries of CB&I and McDermott that are parties to the Business Combination Agreement and McDermott as an alleged control person of CB&I, and another also names certain current and former CB&I officers and employees individually.

Comparison of Rights of Shareholders (see page 184)

McDermott is a Panamanian corporation. CB&I is a Dutch public limited company. The shares of McDermott Common Stock that CB&I shareholders will receive in the Combination will be shares of a Panamanian corporation. McDermott stockholder rights under Panamanian law and CB&I shareholder rights under Dutch law are different. In addition, McDermott’s Articles of Incorporation and Amended and Restated By-Laws contain provisions that are different from CB&I’s Articles of Association.

Material differences include:

Material Tax Consequences of the Combination (see page 200)

Holders of CB&I Common Stock should read “Material Tax Consequences of the Combination” for a discussion of certain material U.S. federal income tax and Dutch dividend withholding tax consequences of the Combination to U.S. holders (as defined herein) of CB&I Common Stock. All holders of CB&I Common Stock are urged to consult their own tax advisors to determine the tax consequences to them (including the application and effect of any state, local or non-U.S. income and other tax laws) of the Combination.

Exchange Agent for the Merger

Computershare Trust Company, N.A. will serve as the exchange agent in connection with the Merger.

Exchange Agent for the Exchange Offer

Computershare Trust Company, N.A. will serve as the exchange agent in connection with the Exchange Offer.

The Information Agent

The information agent for the Exchange Offer is MacKenzie Partners, Inc.

Selected Historical Consolidated Financial Information of McDermott

The following table sets forth selected historical consolidated financial information of McDermott that has been derived from McDermott’s Consolidated Financial Statements as of December 31, 2017, 2016, 2015, 2014 and 2013, and for the years then ended. This disclosure does not include the effects of the Combination.

You should read this financial information in conjunction with the audited Consolidated Financial Statements and the related Notes and Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in McDermott’s Annual Report on Form 10-K for the year ended December 31, 2017 incorporated by reference in this document. See the section entitled “Where You Can Find More Information”

beginning on page 219 of this document. See also the unaudited pro forma combined financial information regarding the proposed Combination set forth elsewhere in this document. McDermott’s historical results are not necessarily indicative of results to be expected in future periods.

Selected Historical Consolidated Financial Information of CB&I

The following table sets forth selected historical consolidated financial information of CB&I that has been derived from CB&I’s Consolidated Financial Statements as of December 31, 2017, 2016, 2015, 2014 and 2013, and for the years then ended. This disclosure does not include the effects of the Combination.

You should read this financial information in conjunction with the audited Consolidated Financial Statements and the related Notes and Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in CB&I’s Annual Report on Form 10-K for the year ended December 31, 2017 incorporated by reference in this document. See the section entitled “Where You Can Find More Information” beginning on page 219 of this document. See also the unaudited pro forma combined financial information regarding the proposed Combination set forth elsewhere in this document. CB&I’s historical results are not necessarily indicative of results to be expected in future periods.

Selected Unaudited Pro Forma Combined Financial Information

The following unaudited pro forma combined statements of operations information for the year ended December 31, 2017 has been prepared to give effect to the Combination as if it had occurred on January 1, 2017. The unaudited pro forma combined balance sheet information as of December 31, 2017 has been prepared to give effect to the Combination as if it had occurred on December 31, 2017.

The pro forma information is not necessarily indicative of what the combined business’ financial position or results of operations actually would have been had the Combination been completed as of the dates indicated. In addition, the unaudited pro forma combined financial information does not purport to project the future financial position or operating results of the combined business. Future results may vary significantly from the results reflected because of various factors, including those discussed in “Risk Factors” beginning on page 25 of this document. The following selected unaudited pro forma combined financial information should be read in conjunction with the “Unaudited Pro Forma Combined Financial Statements” and related notes included in this document beginning on page 167 of this document.

Combined pro forma earnings to fixed charges ratio—2017 pro forma combined earnings were deficient to cover pro forma fixed charges by $547 million.

Comparative Per Share Market Price and Dividend Information

The following table sets forth the closing sale price per share of McDermott Common Stock and CB&I Common Stock as reported on the NYSE as of December 18, 2017, the last trading day before the public announcement of the Combination, and as of March 26, 2018, the most recent practicable trading day prior to the date of this document. The table also shows the implied value of the Combination consideration proposed for each share of CB&I Common Stock as of the same dates. This implied value was calculated by multiplying the closing sale price of a share of McDermott Common Stock on the relevant date and the exchange offer ratio of 2.47221.

The following table sets forth, for the periods indicated, the intra-day high and low sales prices per share for McDermott Common Stock and CB&I Common Stock as reported on the NYSE, which is the principal trading market for both McDermott Common Stock and CB&I Common Stock, and the cash dividends declared per share of McDermott Common Stock and CB&I Common Stock.

The market prices of McDermott Common Stock and CB&I Common Stock will fluctuate between the date of this document and the completion of the Combination. No assurance can be given concerning the market prices of McDermott Common Stock or CB&I Common Stock before the completion of the Combination or McDermott Common Stock after the completion of the Combination. Because the Exchange Offer Ratio is fixed in the Business Combination Agreement, the market value of the McDermott Common Stock that CB&I shareholders will receive in connection with the Combination may vary significantly from the prices shown in the table above. Accordingly, CB&I shareholders are advised to obtain current market quotations for McDermott Common Stock and CB&I Common Stock before deciding whether to vote for adoption of the Business Combination Agreement.