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                                                                   EXHIBIT 24(a)


                                POWER OF ATTORNEY

         WHEREAS, Compass Bancshares, Inc. (the "Company") has agreed to file a
registration statement and amendments thereto under the Securities Act of 1933,
as amended, with respect to the issuance and sale of shares of common stock of
the Company in connection with the acquisition by the Company of MegaBank
Financial Corporation, Englewood, Colorado;

         NOW, THEREFORE, KNOW ALL MEN BY THESE PRESENTS, that the Company and
the undersigned directors and officers of said Company, individually as a
director and/or as an officer of the Company, hereby make, constitute and
appoint each of D. Paul Jones, Jr., Garrett R. Hegel, Jerry W. Powell, and
Daniel B. Graves their true and lawful attorney-in-fact for each of them and in
each of their names, places and steads to sign and cause to be filed with the
Securities and Exchange Commission said registration statement and any
appropriate amendments thereto, to be accompanied by prospectuses and any
appropriately amended prospectuses and any necessary exhibits.

         The Company hereby authorizes said persons or any one of them to
execute said registration statement and amendments thereto on its behalf as
attorney-in-fact for it and its authorized officers, and to file the same as
aforesaid.

         The undersigned directors and officers of the Company hereby authorize
said persons or any one of them to sign said registration statements on their
behalf as attorney-in-fact and to amend, or remedy any deficiencies with respect
to, said registration statements by appropriate amendment or amendments and to
file the same as aforesaid.

         DONE as of this the 26th day of November, 1999.
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                                 COMPASS BANCSHARES, INC.


                                 By:  /s/ D. Paul Jones, Jr.
                                      ----------------------------------------
                                      D. Paul Jones, Jr.
                                      Its Chairman and Chief Executive Officer


                                 /s/ D. Paul Jones, Jr.
                                 ----------------------------------------------
                                 D. Paul Jones, Jr.


                                 /s/ Garrett R. Hegel
                                 ----------------------------------------------
                                 Garrett R. Hegel


                                 /s/ Timothy L. Journy
                                 ----------------------------------------------
                                 Timothy L. Journy


                                 /s/ Charles W. Daniel
                                 ----------------------------------------------
                                 Charles W. Daniel


                                 /s/ W. Eugene Davenport
                                 ----------------------------------------------
                                 W. Eugene Davenport


                                 /s/ Marshall Durbin, Jr.
                                 ----------------------------------------------
                                 Marshall Durbin, Jr.


                                 /s/ Tranum Fitzpatrick
                                 ----------------------------------------------
                                 Tranum Fitzpatrick


                                 /s/ Carl J. Gessler, Jr.
                                 ----------------------------------------------
                                 Carl J. Gessler, Jr.


                                 /s/ John S. Stein
                                 ----------------------------------------------
                                 John S. Stein


                                 /s/ Robert J. Wright
                                 ----------------------------------------------
                                 Robert J. Wright