THIRD SUPPLEMENTAL INDENTURE

Exhibit 4.4

THIRD SUPPLEMENTAL INDENTURE

THIRD SUPPLEMENTAL INDENTURE (this “Third Supplemental Indenture”), dated as of November 2, 2004, among NewMarket Corporation, a Virginia corporation (“NewMarket”), Old Town LLC, a Virginia limited liability company and an indirect wholly-owned subsidiary of NewMarket (the “Guaranteeing Subsidiary”), and Wells Fargo Bank, National Association, as trustee under the Indenture referred to below (the “Trustee”).

W I T N E S S E T H

WHEREAS, Ethyl Corporation, a Virginia corporation and wholly-owned subsidiary of NewMarket (“Ethyl”), has heretofore executed and delivered to the Trustee an indenture, dated as of April 30, 2003 (the “Initial Indenture”), providing for the issuance of 8.875% Senior Notes due 2010 (the “Notes”); and

WHEREAS, pursuant to an Agreement and Plan of Merger, dated as of March 5, 2004 (the “Plan of Merger”), by and among NewMarket, Ethyl and Ethyl Merger Sub, Inc., a wholly-owned subsidiary of NewMarket, NewMarket became the holding company for Ethyl effective as of June 18, 2004 (the “Holding Company Formation”); and

WHEREAS, pursuant to the Supplemental Indenture, dated as of June 18, 2004 (the “Supplemental Indenture” and together with the Initial Indenture, the “Indenture”), among NewMarket, Ethyl, the Guaranteeing Subsidiaries (as defined therein), the other Guarantors named on the signature pages thereto and the Trustee, NewMarket agreed to assume all of Ethyl’s obligations under the Indenture and the Notes; and

WHEREAS, NewMarket Services Corporation, a Virginia corporation and wholly owned subsidiary of NewMarket (“NewMarket Services”) acquired all of the outstanding membership units of Old Town LLC, a Virginia limited liability company (“Old Town”); and

WHEREAS, the Indenture provides that certain newly organized or newly acquired subsidiaries of NewMarket shall execute and deliver to the Trustee a supplemental indenture pursuant to which such subsidiary shall unconditionally guarantee all of NewMarket’s obligations under the Notes and the Indenture; and

WHEREAS, in accordance with Section 4.17 of the Indenture, the Guaranteeing Subsidiary has agreed to execute and deliver to the Trustee a supplemental indenture pursuant to which the Guaranteeing Subsidiary shall unconditionally guarantee all of NewMarket’s Obligations under the Notes and the Indenture on the terms and conditions set forth herein (the “Note Guarantee”); and

WHEREAS, pursuant to Section 9.01 of the Indenture, the Trustee is authorized to execute and deliver this Third Supplemental Indenture.

NOW THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt of which is hereby acknowledged, NewMarket, the Guaranteeing Subsidiary and the Trustee mutually covenant and agree for the equal and ratable benefit of the Holders of the Notes as follows:

1. CAPITALIZED TERMS. Capitalized terms used herein without definition shall have the meanings assigned to them in the Indenture.

2. AGREEMENT TO GUARANTEE. The Guaranteeing Subsidiary hereby agrees as follows:

3. EXECUTION AND DELIVERY. The Guaranteeing Subsidiary agrees that the Note Guarantees shall remain in full force and effect notwithstanding any failure to endorse on each Note a notation of such Note Guarantee.

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4. GUARANTEEING SUBSIDIARY MAY CONSOLIDATE, ETC. ON CERTAIN TERMS.

5. RELEASES.

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6. NO RECOURSE AGAINST OTHERS. No past, present or future director, officer, employee, incorporator, stockholder, member or agent of the Guaranteeing Subsidiary, as such, shall have any liability for any obligations of NewMarket or any Guaranteeing Subsidiary under the Notes, any Note Guarantees, the Indenture or this Third Supplemental Indenture or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each Holder of the Notes by accepting a Note waives and releases all such liability. The waiver and release are part of the consideration for issuance of the Notes. Such waiver may not be effective to waive liabilities under the federal securities laws and it is the view of the SEC that such a waiver is against public policy.

7. NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF NEW YORK SHALL GOVERN AND BE USED TO CONSTRUE THIS THIRD SUPPLEMENTAL INDENTURE BUT WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

8. COUNTERPARTS. The parties may sign any number of copies of this Third Supplemental Indenture. Each signed copy shall be an original, but all of them together represent the same agreement.

9. EFFECT OF HEADINGS. The Section headings herein are for convenience only and shall not affect the construction hereof.

10. THE TRUSTEE. The Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this Third Supplemental Indenture or for or in respect of the recitals contained herein, all of which recitals are made solely by the Guaranteeing Subsidiary and NewMarket.

[Signature page follows]

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IN WITNESS WHEREOF, the parties hereto have caused this Third Supplemental Indenture to be duly executed, all as of the date first above written.

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