<PAGE>

                                                                   Exhibit 4.6.3

                          FIRST SUPPLEMENTAL INDENTURE

          This "Supplemental Indenture", dated as of February 7, 2002, between
the subsidiary of MeriStar Hospitality Operating Partnership, a Delaware limited
partnership, (the "Company"), indicated as the New Guarantor on the signature
pages hereto (the "Guarantor") and U.S. Bank Trust National Association, as
trustee under the indenture referred to below (the "Trustee").

                               W I T N E S S E T H

          WHEREAS, the Company, MeriStar Hospitality Finance Corp. II ("MeriStar
Finance," and together with the Company, the "Issuers"), MeriStar Hospitality
Corporation (the "Parent"), the Subsidiary Guarantors who are parties to the
indenture referred to below, have heretofore executed and delivered to the
Trustee an indenture (the "Indenture"), dated as of December 19, 2001, providing
for the issuance of up to an aggregate principal amount of $250,000,000 of
10-1/2% Senior Notes due 2009 (the "Notes");

          WHEREAS, Section 4.15 of the Indenture provides that under certain
circumstances the Company and the Parent are required to cause the Guarantor to
execute and deliver to the Trustee a supplemental indenture pursuant to which
the Guarantor shall unconditionally guarantee all of the Issuers' Obligations
under the Notes pursuant to a Guarantee on the terms and conditions set forth
herein; and

          WHEREAS, pursuant to Section 9.1 of the Indenture, the Trustee is
authorized to execute and deliver this Supplemental Indenture.

          NOW THEREFORE, in consideration of the foregoing and for other good
and valuable consideration, the receipt of which is hereby acknowledged, the
Guarantor 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 Guarantor hereby agrees, jointly and
severally with all other guarantors under the Indenture, to guarantee the
Issuers' obligations under the Notes on the terms and subject to the conditions
set forth in Article 10 of the Indenture and to be bound by all other applicable
provisions of the Indenture.

          3.   NO RECOURSE AGAINST OTHERS.  No past, present or future director,
officer, employee, incorporator, shareholder or agent of the Guarantor, as such,
shall have any liability for any obligations of any Issuer or any other
guarantor under the Notes, any guarantees under the Indenture, the Indenture or
this 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

<PAGE>

                                                                               2

liability. The waiver and release are part of the consideration for issuance of
the Notes. Such waiver or release may not be effective to waive or release
liabilities under the federal securities laws.

          4.   NEW YORK LAW TO GOVERN. The internal law of the State of New York
shall govern and be used to construe this Supplemental Indenture.

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

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

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

                                       New Guarantor:
                                       -------------

                                       MERISTAR HOSPITALITY FINANCE CORP. III,
                                       a Delaware corporation

                                       By: _____________________________________
                                           Christopher L. Bennett
                                           Senior Vice President and
                                           General Counsel

                                       Trustee:
                                       -------

                                       U.S. BANK TRUST NATIONAL ASSOCIATION,
                                       as Trustee

                                       By: _____________________________________
                                           Name: Adam Berman
                                           Title: Trust Officer