Filed by Millennium Chemicals Inc.
                       Pursuant to Rule 425 under the Securities Act of 1933 and
  Deemed Filed Pursuant to Rule 14a-12 under the Securities Exchange Act of 1934

                                      Subject Company: Millennium Chemicals Inc.
                                                     Commission File No. 1-12091

Date: April 21, 2004

This filing contains the text of a memo sent to all employees of Millennium on
April 21, 2004. These materials are being filed pursuant to Rule 425 under the
Securities Act of 1933.
                                      # # #

     MILLENIUM                                       20 Wight Avenue
     CHEMICALS                                       Hunt Valley, MD  21030

                                                     Tel  (410) 229-4401
                                                     Fax  (410) 229-4595
                                                     BOB.LEE@MILLENNIUMCHEM.COM

TO:       All Employees                              DATE:  April 21, 2004

FROM:     Bob Lee                                    LOCATION:  Hunt Valley, MD
          President and Chief Executive Officer

SUBJECT:  BART DE JONG TO HEAD GLOBAL TIO2 BUSINESS UPON THE CLOSE OF OUR
          PROPOSED BUSINESS COMBINATION


ANNOUNCEMENT FROM DAN SMITH:

As we continue to plan for the integration of Millennium into Lyondell, we
remain committed to keeping you advised of integration planning activities and
organizational decisions, as they are made.

I am pleased to announce that Bart de Jong will become General Manager, TiO2,
upon the close of our proposed business combination with Millennium Chemicals
Inc., expected in the third quarter of this year. In this capacity, he will
directly report to me, and assume overall responsibility for Millennium's global
titanium dioxide (TiO2) business. The business will continue to be operated out
of Baltimore, MD, with both business and support resources necessary for the
ongoing needs of the business.

In the interim, Bart will continue as Vice President of Corporate Development
and co-manager of the joint Lyondell-Millennium Integration Team. The
Integration Team is working on the design of each of the organizational units
that will report into the General Manager position while Bart and I work
together to confirm the leadership team members for each function that will be
reporting to Bart.

These materials contain forward-looking statements within the meaning of the
Private Securities Litigation Reform Act of 1995. Such statements include, but
are not limited to, statements about the benefits of the proposed transaction


between Lyondell Chemical Company ("Lyondell") and Millennium Chemicals Inc.
("Millennium"), including financial and operating results, Lyondell's plans,
objectives, expectations and intentions and other statements that are not
historical facts. Such statements are based upon the current beliefs and
expectations of Lyondell's management and are subject to significant risks and
uncertainties. Actual results may differ materially from those set forth in the
forward-looking statements. The following factors, among others, could affect
the proposed transaction and the anticipated results: approval by Lyondell's and
Millennium's respective shareholders, amendments to Lyondell's and Millennium's
respective credit facilities, the expiration or termination of any applicable
waiting period under the Hart-Scott-Rodino Act, the receipt of other competition
law clearances and the parties' ability to achieve expected synergies in the
transaction within the expected timeframes or at all. Additional factors that
could cause Lyondell's results to differ materially from those described in the
forward-looking statements can be found in Lyondell's Annual Report on Form 10-K
for the year ended December 31, 2003, which was filed with the Securities and
Exchange Commission (the "SEC") on March 12, 2004.

Lyondell and Millennium will file a joint proxy statement/prospectus with the
SEC in connection with the proposed transaction. INVESTORS AND SECURITY HOLDERS
ARE URGED TO READ THAT DOCUMENT, WHEN IT BECOMES AVAILABLE, BECAUSE IT WILL
CONTAIN IMPORTANT INFORMATION. Investors and security holders may obtain a free
copy of that document (when it becomes available) and other documents filed by
Lyondell and Millennium with the SEC at the SEC's web site at www.sec.gov. The
joint proxy statement/prospectus (when it becomes available) and the other
documents filed by Lyondell may also be obtained free from Lyondell by calling
Lyondell's Investor Relations department at (713) 309-4590.

The respective executive officers and directors of Lyondell and Millennium and
other persons may be deemed to be participants in the solicitation of proxies in
respect of the proposed transaction. Information regarding Lyondell's executive
officers and directors is available in its proxy statement filed with the SEC by
Lyondell on March 16, 2004, and information regarding Millennium's directors and
its executive officers is available in Millennium's Annual Report on Form 10-K
for the year ended December 31, 2003, which was filed with the SEC on March 12,
2004. Other information regarding the participants in the proxy solicitation and
a description of their direct and indirect interests, by security holdings or
otherwise, will be contained in the joint proxy statement/prospectus and other
relevant materials to be filed with the SEC.