Filed by Lyondell Chemical Company

Pursuant to Rule 425 under the Securities Act of 1933 and

Deemed Filed Pursuant to Rule 14a-6 under the Securities Exchange Act of 1934

Form S-4 Registration Statement File No.: 333-114877

Subject Company: Millennium Chemicals Inc.

Additional Information:

On October 15, 2004, Lyondell Chemical Company (“Lyondell”) filed with the Securities and Exchange Commission (the “SEC”) the definitive joint proxy statement/prospectus regarding the proposed transaction between Lyondell and Millennium Chemicals Inc. (“Millennium”). Investors and security holders are urged to read that document and any other relevant documents filed or that will be filed with the SEC 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 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 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.

Forward-Looking Statements:

This release 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 and 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 SEC on March 12, 2004, and Lyondell’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2004, which was filed with the SEC on November 8, 2004.

This filing contains slides used by Lyondell in presentations during analyst conferences on November 10-12, 2004. This information is being filed pursuant to Rule 425 under the Securities Act of 1933.

# # #

Positioned For The Cyclical Upturn

Boston Visits November 10 – 11, 2004

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 September 30, 2004, which was filed with the SEC on November 8, 2004.

In addition, on October 15, 2004, Lyondell filed with the SEC the definitive joint proxy statement/prospectus regarding the proposed transaction between Lyondell and Millennium. Investors and security holders are urged to read that document and any other relevant documents filed or that will be filed with the SEC 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 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 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.

Reconciliations of GAAP financial measures to non-GAAP financial measures are provided at the end of this presentation.

2

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

3

The Following Areas Have Been The Principal Areas Of Investor Interest Over The Past Weeks:

What is the outlook for TiO2?

Impact of oil price?

Will U.S. ethylene assets be able to compete in the future?

What is the potential impact of PO capacity additions? Are strong LCR profits sustainable?

What is peak profitability?

4

TiO2 Manufacturing Locations

Ashtabula, OH

Baltimore, MD

Stallingborough, UK

Le Havre, France

Thann, France

Bahia, Brazil

Paraiba, Brazil (Mine)

Kemerton, Australia

Bunbury, Australia

5

TiO2 Demand and Supply:

Demand – 4.1 MM mtpa; $8 billion

Capacity – ~4.8 MM mtpa

End-Use Market

Ind. Coatings

Arch. Paint

Paper

Plastics

Other

Geographical Region C&S

America

North America

Asia

EE / ME / AF

Europe

Capacity

Others

Kronos

Tioxide

Kerr-McGee

MCH

DuPont

Source: Millennium Estimates and Published Information

6

Chloride Is Typically The Preferred Process Vs. Sulfate

Product Attributes

End use dependent

Better purity and particle size control

Finishing is similar

Process Attributes

Continuous process

Fewer process steps

Fewer people

Smaller facility footprint

Less waste produced

7

Chloride Is A Continuous Process With Fewer Steps And Less Waste

Sulfate-

batch

Sulfuric Acid

Digestion

Clarification

Hydrolysis

Filtration

Calcination

Finishing

Dilute Acid to Gypsum Recovery Iron recovery or disposal

Titanium Ore

Chloride-

continuous

Chlorination

Purification

Oxidation

Finishing

Coke

Recycled Cl2

8

Global Capacity Additions Have Typically Utilized Chloride Technology

Installed Capacity (000 MT)

6,000

5,000

4,000

3,000

2,000

1,000

0

1980 1982 1984 1986 1988 1990 1992

1994 1996 1998 2000 2002

Sulfate Chloride

Source: Millennium, Published Information

9

There Are Minimal Announced Capacity Additions

M Tonnes

Operating Rate

Demand

Capacity

6,000 5,500 5,000 4,500 4,000 3,500 3,000 2,500 2,000

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

100% 95% 90% 85% 80% 75% 70% 65% 60%

Operating Rate

Source: Millennium

10

The Following Areas Have Been The Principal Areas Of Investor Interest Over The Past Weeks:

What is the outlook for TiO2?

Impact of oil price?

Will U.S. ethylene assets be able to compete in the future?

What is the potential impact of PO capacity additions? Are strong LCR profits sustainable?

What is peak profitability?

11

The US Economy Is Benefiting From Economic Stimulus

Stimulus Change DGDP Leads to After 1 Year 2 Years

Fed Rate Reduction 100 BP 0.6 1.7

Real Dollar Decline 10% 0.4 1.6

Income Tax Reduction 1% of GDP 0.4 0.8

Stock Price Increase 20% 0.4 0.8

Oil Price Decline $10/bbl 0.2 0.4

* Source: Fed Reserve, Jan. 1999

12

Chemical and Plastics Demand Grows Rapidly As Economies Develop

Polyethylene Consumption By Nation

US

Singapore

Taiwan

Korea

WE

Malaysia

Japan

Thailand

China India Indonesia

PE Consumption/capita, lbs

12 0 10 0 8 0 6 0 4 0 2 0 0

0 5 , 0 0 0 10 , 0 0 0 15 , 0 0 0 2 0 , 0 0 0 2 5 , 0 0 0 3 0 , 0 0 0 3 5 , 0 0 0 4 0 , 0 0 0

2000 GDP/Capita

Source: CMAI 2001

13

Profitability Is Driven By Supply/Demand Fundamentals

Crude Oil vs. Equistar EBITDA

EBITDA

550 450 350 250 150 50 -50

1H99 1H00 1H01 1H02 1H03 1H04

40 35 30 25 20 15 10 5 0

Crude Price

EBITDA

Crude Price

U.S. Ethylene Operating Rates vs. Equistar EBITDA

EBITDA

550 450 350 250 150 50 -50

1H99 1H00 1H01 1H02 1H03 1H04

100 95 90 85 80 75 70

Operating Rate

EBITDA

Operating Rate

Source: Platt’s, CMAI

14

Our Results Reflect Improving Conditions

EBITDA $MM

Quarterly EBITDA

500 450 400 350 300 250 200 150 100 50 0 -50

Q1 2003 Q2 2003 Q3 2003 Q4 2003 Q1 2004 Q2 2004 Q3 2004

IC&D 100% Equistar 100% LCR

15

The Following Areas Have Been The Principal Areas Of Investor Interest Over The Past Weeks:

What is the outlook for TiO2?

Impact of oil price?

Will U.S. ethylene assets be able to compete in the future?

What is the potential impact of PO capacity additions? Are strong LCR profits sustainable?

What is peak profitability?

16

Ethylene Is Recovering From A Significant Trough

Ethylene Supply/Demand Balance—North America

Bln lbs

Rest of World

Effective Operating Rate (at 96% on-stream-time)

N. America

N. America Demand

110 100 90 80 70 60 50 40

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Operating Rate

100% 95% 90% 85% 80% 75% 70% 65%

Source: CMAI / Equistar (September 2004)

17

Liquid Cracking Provides an Advantage vs. Ethane Raw Materials

Equistar Capability

NGL 37% Liquid 63% N. American Industry (ex. Equistar) Liquid 25% NGL 75%

Liquid Cracking Variable Cost Advantage vs. NGL Ethane – Light Naphtha Cost of Ethylene Spread

Average

¢/lb ethylene

7 6 5 4 3 2 1 0

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 H1 2004

Source: CMAI, Chem Data, and Lyondell 18

Future Ethylene Capacity Additions Favor a Growing Liquid Raw Material Advantage

2004 — 2009

2003 Demand Blbs Demand Growth Blbs Olefins Plant Supply Growth Blbs DBlbs

Ethylene 226 56 55 (1)

Propylene 134 38 15 (23)

Ethylene / Propylene 1.7 1.5 3.7 —

Source: CMAI September 2004

19

The Following Areas Have Been The Principal Areas Of Investor Interest Over The Past Weeks:

What is the outlook for TiO2?

Impact of oil price?

Will U.S. ethylene assets be able to compete in the future?

What is the potential impact of PO capacity additions?

Are strong LCR profits sustainable? What is peak profitability?

20

Globally Propylene Oxide Is Following A Similar Trend With Minimal Supply Additions

B Lbs/yr

Operating Rate

Demand

Supply

20 18 16 14 12 10 8 6 4 2 0

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Operating Rate

100% 90% 80% 70% 60% 50%

Source: LYO, SRI

21

PO Technology is Entering its Third Generation of Innovation

1st Generation 2nd Generation 3rd Generation

Technology Chlorohydrin Peroxidation Direct Oxidation

Initial Application 1910 1960/70s 2000/10

Key Producers Dow POSM—Lyondell, Shell

China (several) POTBA – Lyondell

PO/Cumene – Sumitomo/

Lyondell JV

Development Efforts PO/H2O2—Dow/BASF Lyondell

22

Steps Toward Increased IC&D Cash Flow $ MM/Yr

600 500 400 300 200 100 Base

Potential Cash Improvement From 2003

Complete PO-11 Capital Spend

Convert PO/SM Purchases on Production

1999 PO / TDI SM Margins

MTBE Resolution

Sell-out at 1995 PO / TDI / SM Margins

23

The Following Areas Have Been The Principal Areas Of Investor Interest Over The Past Weeks:

What is the outlook for TiO2?

Impact of oil price?

Will U.S. ethylene assets be able to compete in the future?

What is the potential impact of PO capacity additions?

Are strong LCR profits sustainable?

What is peak profitability?

24

LCR Important Cash Generator – Operating Reliability and Crude Deliveries Drive Strong Performance

MB/day

300 250 200 150 100 50 0

Net Distribution To LYO, $MM

CSA Spot Mkt

1Q02 2Q02 3Q02 4Q02 1Q03 2Q03 3Q03 4Q03 1Q04 2Q04 3Q04

2 22 49 7 67 69 55 32 54 89 138

25

Industry Margins Have Rebounded with Growing Worldwide Demand & Limited Refining Capacity

WTI Crude Oil Refining Margin

3/2/1 Refining Spread ($/Bbl) $12.0 $10.0 $8.0 $6.0 $4.0 $2.0 $0.0

Jul-02

Sep-02 Nov-02 Jan-03 Mar-03 May-03 Jul-03 Sep-03 Nov-03 Jan-04 Mar-04 May-04 Jul-04 Sep-04

Source: Platt’s

26

The Following Areas Have Been The Principal Areas Of Investor Interest Over The Past Weeks:

What is the outlook for TiO2?

Impact of oil price?

Will U.S. ethylene assets be able to compete in the future?

What is the potential impact of PO capacity additions?

Are strong LCR profits sustainable?

What is peak profitability?

27

Lyondell Has Maintained Ethylene Chain Leverage While Diversifying Total Chemical Leverage

Pounds / Share

1994 Jan. 1, 2004 Post Transaction Closing

Petrochemicals

Ethylene 45 46.5 47.5

Styrene — 16.5 12

Propylene Oxide — 13.5 10

TDI — 3 2.5

Acetic Acid — — 5

TiO2 — — 6

45 79.5 83

Derivatives

Polyolefins 5.5 24 24.5

Ethylene Oxygenates — 6.5 6.5

PO Derivatives — 9.5 7

Vinyl Acetate (VAM) — — 3.5

5.5 40 41.5

Notes: Lbs refers to capacity times ownership percentage.

1994 2004 Post-closing (pro forma)*

Share Count 80 MM 177 MM 245 mm

* Assumed 1.05 exchange ratio

28

Enterprise Earnings Capability Far Exceeds Recent Results

(Current Ownership – Pre-Millennium Transaction)

Cycle EBITDA Potential $MM

Recession/ Trough

Pre-Recession $6.90 / share

Peak $1.40 / share

2003 Proportional Interest, Dividends & Capital

3000 2500 2000 1500 1000 500 0

2003 1999/2000 1995 Margins1 1988 Margins1 Margins 1

LCR IC&D Equistar

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.

29

There Is A Significant Amount of Accessible Debt

Accessible Debt * $MM

1,400 1,200 1,000 800 600 400 200 0 $278

$900 $800 $730 $700 $700

$500 $485

$100 $1 $150

Lyondell Equistar Millennium Lyondell Equistar Millennium Lyondell Equistar Millennium Lyondell Equistar Millennium Lyondell Equistar Millennium

2004 2005 2006 2007 2008

Lyondell 9 3/8% ACC Debenture

Lyondell 9 1/2% Sr. Secured Notes Series C

Equistar 6 1/2% Notes

Millennium 7% Senior Unsecured Notes due 2006

Lyondell 9 5/8% Sr. Secured Notes Series A

Lyondell 11 1/8% Sr. Secured Notes Series D

Equistar 10 1/8% Senior Notes

Millennium 9 1/4% Senior Unsecured Notes due 2008

Lyondell 9 7/8% Sr. Secured Notes Series B

Equistar 11.2% Medium Term Notes

Equistar 10 5/8% Senior Notes

* As of October 2004

Accessible debt is shown for the first year in which it is callable and does not include subordinated debt. Debt with make-whole provisions is shown at maturity, including the $900MM Senior Secured Notes Series A due 2007 (Lyondell) and $700MM Senior Notes due 2008 (Equistar)

Millennium: Post Transaction

30

De-Leveraging Benefits All Stakeholders

Impact of Lyondell debt reduction at constant capitalization1

$3 Billion (with MCH)

Debt to Capitalization 45%

Avoided Interest Expense $ 300MM / Year

Earnings Improvement 80¢ / share

Share Price Improvement at Constant Capitalization $12.25 / share 2

1 Capitalization = debt + book value of equity + minority interest

2 Assumes 245MM shares outstanding

31

Equistar Chemicals, LP

Reconciliation of Net Income (Loss) to EBITDA

For the six-month periods ended June 30 (Millions of Dollars)

1999 2000 2001 2002 2003 2004

Net income (loss) $49 $208 $(107) $(1,207) $(195) $48

Add:

Depreciation and amortization 147 152 159 147 154 153

Interest expense, net 84 89 91 102 102 110

Cum. effect of accounting change - - - - 1,053 - -

EBITDA $280 $449 $143 $95 $61 $311

32

LYONDELL CHEMICAL COMPANY

RECONCILIATION OF NET INCOME (LOSS) TO EBITDA

(Millions of dollars)

Q1 2003 Q2 2003 Q3 2003 Q4 2003 Q1 2004 Q2 2004 Q3 2004

Lyondell net income (loss) $(113) $(68) $(44) $(77) $(15) $3 $50

Add: Provision for (benefit from) income tax (55) (39) (27) (58) (9) 3 26

Interest expense, net 83 99 106 104 109 108 108

Depreciation and amortization 57 61 66 66 63 64 59

(Income) loss from equity investment in Equistar 100 32 26 70 (6) (33) (54)

Income from equity investment in LCR (19) (37) (43) (45) (56) (63) (89)

Lyondell EBITDA $53 $48 $84 $60 $86 $82 $100

Equistar net income (loss) $(146) $(49) $(40) $(104) $5 $43 $72

Add: Depreciation and amortization 78 76 76 77 76 77 81

Interest expense, net 49 53 51 54 55 55 55

Equistar EBITDA $(19) $80 $87 $27 $136 $175 $208

Proportionate Share—70.5% $(14) $57 $61 $19 $96 $123 $147

LCR net income $28 $58 $69 $73 $91 $103 $147

Add: Depreciation and amortization 28 29 28 28 30 28 29

Interest expense, net 10 9 8 9 10 8 6

LCR EBITDA $66 $96 $105 $110 $131 $139 $182

Proportionate Share—58.75% $39 $56 $62 $65 $77 $82 $107

Lyondell and Proportionate Share of Equity Investments—EBITDA

Lyondell EBITDA $53 $48 $84 $60 $86 $82 $100

70.5% of Equistar EBITDA (14) 57 61 19 96 123 147

58.75% of LCR EBITDA 39 56 62 65 77 82 107

Lyondell and Proportionate Share of Equity Investments $78 $161 $207 $144 $259 $287 $354

33

LYONDELL CHEMICAL COMPANY

RECONCILIATION OF LCR NET INCOME (LOSS) TO EBITDA

(Millions of dollars)

Q1 2002 Q2 2002 Q3 2002 Q4 2002 (b) Q1 2003 Q2 2003 Q3 2003 Q4 2003 1Q 2004 2Q 2004 3Q 2004

Net income (loss) $41 $63 $50 $59 $28 $58 $69 $73 $91 $103 $147

Add: Depreciation and amortization 29 30 28 29 28 29 28 28 30 28 29

Interest expense, net 8 7 8 9 10 9 8 9 10 8 6

LCR EBITDA $78 $100 $86 $97 $66 $96 $105 $110 $131 $139 $182

(a) EBITDA for LCR for the three months ended September 30, 2001 was originally reported as $116 million and was restated to include extraordinary charges related to early debt retirement, currently reflected in other expense, net.

(b) EBITDA for the three months ended December 31, 2002 was originally reported as $98 million and was restated to include extraordinary charges related to early debt retirement, currently reflected in other expense, net.

RECONCILIATION OF LCR NET CASH DISTRIBUTIONS

Q1 2002 Q2 2002 Q3 2002 Q4 2002 Q1 2003 Q2 2003 Q3 2003 Q4 2003 1Q 2004 2Q 2004 3Q 2004

Investment in LCR at beginning of quarter $29 $54 $71 $54 $68 $20 $1 $(14) 3 5 (20) Add: Equity in income (loss) of LCR 27 39 32 37 19 37 43 45 56 63 89 Other comprehensive loss due to minimum pension liability - - - (16) - - - 4 - - -Accrued interest converted to capital - - - - - 10 - - - - - Contribution payable to LCR - - - - - 3 (3) - - - - Other - - - - - - - - - - 1 Less: Investment in LCR at end of quarter (54) (71) (54) (68) (20) (1) 14 (3) (5) 20 68

Net cash distributions from

(contributions to) LCR $2 $22 $49 $7 $67 $69 $55 $32 $54 $88 $138

Distributions from LCR $24 $27 $63 $12 $88 $69 $58 $38 $63 $97 $148 Contributions to LCR (22) (5) (14) (5) (21) - (3) (6) (9) (9) (10)

Net cash distributions from

(contributions to) LCR $2 $22 $49 $7 $67 $69 $55 $32 $54 $88 $138

34

Lyondell Chemical Company

Reconciliation of Net Income (Loss) to EBITDA For the Twelve Months Ended December 31, 2003 and Hypothetical Net Income to Hypothetical EBITDA

Assuming Historical Industry Margin Conditions

Hypothetical Results Using

(Millions of dollars) 2003 Actual 1999/2000 Margins 1 1995 Margins 1 1988 Margins 1

Lyondell net (loss) income $(302) $190 $900 $1,155

Add: (Benefit from) provision for income tax 2 (179) 100 485 620

Interest expense, net 3 392 390 390 390

Depreciation and amortization 4 250 250 250 250

Loss (income) from equity investment in Equistar 228 (170) (940) (1,280)

Income from equity investment in LCR (144) (145) (145) (145)

Lyondell EBITDA $245 $615 $940 $990

Equistar net income (loss) $(339) $225 $1,315 $1,795

Add: Depreciation and amortization 4 307 310 310 310

Interest expense, net 3 207 205 205 205

Equistar EBITDA $175 $740 $1,830 $2,310

Proportionate Share—70.5% $123 $520 $1,290 $1,630

LCR net income $228 $230 $230 $230

Add: Depreciation and amortization 113 115 115 115

Interest expense, net 36 35 35 35

LCR EBITDA $377 $380 $380 $380

Proportionate Share—58.75% $222 $225 $225 $225

Lyondell and Proportionate Share of Equity Investments—EBITDA

Lyondell EBITDA $245 $615 $940 $990

70.5% of Equistar EBITDA 123 520 1,290 1,630

58.75% of LCR EBITDA 222 225 225 225

Lyondell and Proportionate Share of Equity Investments $590 $1,360 $2,455 $2,845

1 Using ChemData/CMAI industry margins for Lyondell and Equistar products, excluding MTBE, for the relevant periods applied to current Lyondell and Equistar capacities at 100% utilization and using constant LCR earnings at 2003 level. Except for 2003 Actual, this is not intended to present either historical or forecast earnings of Lyondell, Equistar or LCR.

2 Assumes 35% tax rate for hypothetical data.

3 Assumes constant capitalization and interest rates.

4 Assumes current capacity, book values and estimated useful lives.

35