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                                                                    EXHIBIT 4.19


               AMENDMENT TO COMMON SECURITIES GUARANTEE AGREEMENT

         This Amendment to Common Securities Guarantee Agreement (the
"Amendment") is made as of December 17, 1999 by and between Olympia Financial
Corp., a Delaware corporation, and The Bank of New York, a New York banking
corporation.

                                   WITNESSETH

         WHEREAS, Olympia Financial Corp., successor by merger to ONBANCorp,
Inc., (the "Guarantor"), and The Bank of New York, as trustee (in such capacity,
the "Capital Securities Guarantee Trustee") previously entered into a Common
Securities Guarantee Agreement dated as of February 4, 1997 (the "Guarantee
Agreement") by which the Guarantor agreed to make certain payments to the
Holders of Common Securities issued pursuant to an Amended and Restated
Declaration of Trust dated as of February 4, 1997 by and between Guarantor, in
its capacity as Sponsor, The Bank of New York, as property trustee, and The Bank
of New York (Delaware), a Delaware banking corporation, as Delaware trustee; and

         WHEREAS, ONBANCorp, Inc. has been merged with and into Olympia
Financial Corp., a wholly owned subsidiary of M&T Bank Corporation, a New York
corporation; and

         WHEREAS, the Administrative Trustees of the Trust have changed the name
of the Trust from "OnBank Capital Trust I" to "M&T Capital Trust III;" and

         WHEREAS, the Guarantor and the Guarantee Trustee desire to amend the
Guarantee Agreement to provide for the change of the Guarantor from "ONBANCorp,
Inc." to "Olympia Financial Corp.," and the name of the Trust from "OnBank
Capital Trust I" to "M&T Capital Trust III."

         NOW THEREFORE, in consideration of the agreements and obligations set
forth herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, each party to this Amendment, for
the benefit of the other parties and for the benefit of the Holders, hereby
amends the Guarantee Agreement, and agrees, intending to be legally bound, as
follows:

SECTION 1.  DEFINITIONS.

         1.1. For all purposes of this Amendment, except as otherwise expressly
provided, terms used but not defined in this Amendment shall have the meanings
assigned to them in the Guarantee Agreement.

         1.2. The definition of "Guarantor" in the preamble of the Guarantee
Agreement is amended to mean Olympia Financial Corp., a Delaware corporation.



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         1.3.  The definition of "Issuer" in the preamble of the Guarantee
Agreement is amended to read "M&T Capital Trust III."

SECTION 2.  MISCELLANEOUS.

         2.1. CONTINUING AGREEMENT. The Guarantee Agreement shall not be amended
by this Amendment except as specifically provided in this Amendment and, amended
as so specifically provided, the Guarantee Agreement shall remain in full force
and effect. References in the Guarantee Agreement to "this Guarantee Agreement"
shall be deemed to be references to the Guarantee Agreement as amended by this
Amendment.

         2.2. CONFLICTS. In the event of a conflict between the terms and
conditions of the Guarantee Agreement and the terms and conditions of this
Amendment, the terms and conditions of this Amendment shall prevail.

         2.3. COUNTERPART ORIGINALS. The parties may sign any number of copies
of this Amendment. Each signed copy shall be an original, but all of them
together represent the same agreement.

         2.4. HEADINGS, ETC. The headings of the sections of this Amendment have
been inserted for convenience of reference only, are not to be considered a part
hereof, and shall in no way modify or restrict any of the terms or provisions
hereof.

         IN WITNESS WHEREOF the parties have caused this Amendment to be
executed as of the day and year first above written.

                                   OLYMPIA FINANCIAL CORP.

                                   as Guarantor

                                   By:   /s/ Michael P. Pinto
                                         -----------------------------------
                                         Michael P. Pinto
                                         Chairman of the Board and President

                                   THE BANK OF NEW YORK
                                   as Guarantee Trustee,
                                   and not in its individual capacity

                                   By:   /s/ Iliana A. Arciprete
                                         -----------------------------------
                                         Iliana A. Arciprete
                                         Assistant Treasurer



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