Lyondell Has Built a Major Global Chemical Enterprise

1. Positioned For The Cyclical UpturnBanc of AmericaSeptember 21, 2004Dan F. SmithPresident and Chief Executive Officer

2. This presentation contains 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 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, and Lyondell’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2004, which was filed with the SEC on August 6, 2004. In addition, on September 16, 2004, Lyondell filed with the SEC an amendment to its registration statement on Form S-4 (as amended, the “Form S-4”) containing a preliminary joint proxy statement/prospectus regarding the proposed transaction between Lyondell and Millennium.  The definitive joint proxy statement/prospectus will be sent to holders of Lyondell's and Millennium's common stock when it becomes available. Investors and security holders are urged to read that document and any other relevant documents filed or that will be filed with the SEC, including the definitive joint proxy statement/prospectus that will be part of the definitive registration statement, as they become available, because they contain, or will contain, important information.  Investors and security holders may obtain a free copy of the definitive joint proxy statement/prospectus (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 definitive 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 the proxy statement filed with the SEC by Lyondell on March 16, 2004 and in the Form S-4, and information regarding Millennium’s directors and its executive officers is available in Millennium’s Annual Report on Form 10-K/A for the year ended December 31, 2003, which was filed with the SEC on April 27, 2004, and in the Form S-4.  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 definitive joint proxy statement/prospectus and other relevant materials filed with the SEC, as they become available. Reconciliations of GAAP financial measures to non-GAAP financial measures are provided at the end of this presentation.

3. Lyondell Has Built a Major Global Chemical Enterprise • Global producer of basic chemicals, polymers, and fuels • Built one of the world’s leading chemical companies through: • Acquisitions and joint ventures • New investment where differential • Our value proposition • Excel at low-cost operation in a mature industry • Return cash flow to investors: • Dividends and interest • Debt reduction

4. 3rd Largest Chemical Company in North America (Post-Transaction) 2003 Sales ($ in millions) $35,000 $30,000 $25,000 $20,000 $15,000 $10,000 $5,000 $0 LZ EC CK VAL DD RPM ALB ECL POL CYT GLK HPC NCX ARJ FUL EMN FOE PPG DOW WLM ROH SHW SHLM Pro Forma Lyondell

5. Four Principal Entities Will Form The Lyondell Enterprise Entity Intermediate Chemicals (IC&D) Equistar Millennium LYONDELL-CITGO Refining

6. Our Products Have Become Basic Necessities In Developed Economies 2003 Sales Revenue * Includes pending MCH transaction and proportional share of LCR

7. Chemical and Plastics Demand Grows Rapidly As Economies Develop Polyethylene Consumption By Nation US Singapore Taiwan Korea WE Japan Malaysia Thailand China India Indonesia Source: CMAI 2001

8. Our Products Tend To BeRaw Material And Capital Cost Intensive … Example: Ethylene/PE Production Costs Source: CMAI July 2003 costs 5-year capital recovery.

9. … But Profitability Is Driven By Supply/Demand Fundamentals U.S. Ethylene Operating Rates vs. Equistar EBITDA Crude Oil vs. Equistar EBITDA Source: Platt’s, CMAI

10. Ethylene Is Recovering From A Significant Trough Source: CMAI / Equistar (September 2004)

11. Globally Propylene Oxide Is Following A Similar Trend With Minimal Supply Additions Operating Rate Demand Supply Source: LYO, SRI

12. The TiO2 Supply/Demand Outlook Is Similar To Propylene Oxide Operating Rate M Tonnes Demand Capacity Source: Millennium, SRI

13. U.S. Refining Is Operating Near Full Capacity Operating Rate Capacity Million Barrels Per Calendar Day Utilization Crude Oil Supply Source: EIA

14. Leading Product Positions Create Significant Earnings Leverage Intermediate Chemicals (IC&D) Equistar Millennium 1 Capacities as of January 2004 2 Includes 100% of joint venture volumes 3 Does not include refinery-grade material or production from the product flexibility unit at Equistar’s Channelview facility. Based on 1¢/gal change

15. Each Entity Within The Lyondell Enterprise Benefits From Differentiation CompanyDifferentiation IC&D - Technology leadership - Global position Equistar - Raw material flexibility - Liquid raw material advantage Millennium * - Efficient process technology - Global position LCR - PDVSA Heavy Crude Contract * Post Millennium Transaction

16. For Example, Liquid Cracking Provides an Advantage vs. Ethane Raw Materials Liquid Cracking Variable Cost Advantage vs. NGL Ethane – Light Naphtha Cost of Ethylene Spread Equistar Capability NGL 37% Liquid 63% Average ¢/lb ethylene N. American Industry (ex. Equistar) Liquid 25% NGL 75% Source: CMAI, Chem Data, and Lyondell

17. In Summary, Our Businesses Are Well Positioned for the Up-Cycle • Improving Global Economy • Tightening Supply/Demand Outlook • Significant Volumetric Leverage • Differentiated Positions

18. Our Results Reflect Improving Conditions EBITDA $MM Quarterly EBITDA

19. Enterprise Earnings Capability Far Exceeds Recent Results (Current Ownership – Pre-Millennium Transaction) Cycle EBITDA Potential Peak Pre- Recession Recession/ Trough $1.40 / share $6.90 / share 2003 Proportional Interest, Dividends & Capital 1 1 1 1 Chem Data/CMAI industry margins conditions for IC&D and Equistar products (ex. MTBE) applied to current capacities and ownership, LCR 2003 EBITDA. Note: Assumes 2003 capital structure; 175 MM shares.

20. We Have A Simple, Focused Financial Strategy • Maintain Sufficient Liquidity • Repay Debt • Create Value For Our Stakeholders

21. De-Leveraging Benefits All Stakeholders Impact of Lyondell debt reduction at constant capitalization1 2 3 1 Capitalization = debt + book value of equity + minority interest 2 Assumes 175MM shares outstanding 3 Assumes 245MM shares outstanding

22. * Includes asset impairment charge of $103, reorganization, office and plant closure costs of $18 and $5 minority interest.

25. * Includes asset impairment charge of $103, reorganization, office and plant closure costs of $18 and $5 minority interest.

27. * Includes asset impairment charge of $103, reorganization, office and plant closure costs of $18 and $5 minority interest.