DATE:  MAY 24, 2001
CONTACT: JAMES W. LOKEY
TITLE: PRESIDENT AND CHIEF EXECUTIVE OFFICER
PHONE NUMBER: 805/473-6828
NASDAQ SYMBOL: "MDST"
WEB SITE: www.midstatebank.com

FILED BY MID-STATE BANCSHARES
PURSUANT TO RULE 425 UNDER THE
SECURITIES ACT OF 1933
SUBJECT COMPANY: AMERICORP
SECURITIES EXCHANGE
ACT FILING NO.: 000-23925


                       MID-STATE BANCSHARES AND AMERICORP
                 ANNOUNCE AN AMENDMENT TO THEIR MERGER AGREEMENT
                TO NO LONGER MANDATE POOLING ACCOUNTING TREATMENT
                        AND TO PROVIDE FOR CASH ELECTION

ARROYO GRANDE, California- Chairman Carrol R. Pruett of Mid-State Bancshares
(Mid-State) announced today that the Boards of Directors of Mid-State Bancshares
and Americorp have agreed to amend their definitive agreement to merge to
account for the transaction as a purchase and thereby no longer require the use
of pooling accounting. The Financial Accounting Standards Board (the "FASB") has
announced changes to these accounting rules that could benefit the shareholders
of both corporations. This will enable Mid-State to take advantage of the
proposals to change the accounting treatment for the merger.

Mr. Pruett explained, "We have been advised that the FASB has proposed that
goodwill and other intangibles with indefinite lives would no longer be
systematically amortized to income, but rather, evaluated periodically for
impairment. This alternative would allow Mid-State additional flexibility
compared to the `pooling of interests' methods, including the ability to
repurchase shares of company stock."

"The recent decline in the market price of Mid-State makes the repurchase of
outstanding shares an attractive alternative that would help to eliminate excess
capital and improve earnings per share," added James W. Lokey, President and
CEO. "The flexibility of purchase accounting appears to present a `win-win'
alternative for the Company and its shareholders." The stock repurchase program
for Mid-State Bancshares will be reinstated immediately.

In addition, the amendment will allow Americorp shareholders the opportunity to
receive up to forty percent of the transaction in cash in lieu of shares of
Mid-State inclusive of fractional interests and dissenter's rights, at the
election of Americorp shareholders. "It is especially appealing to be able to
offer a cash alternative to those of our shareholders who may wish to receive
it," commented Robert Lagomarsino, Chairman of Americorp.



Mid-State Bancshares continues to expect the transaction to close late in the
third quarter 2001, pending regulatory and Americorp shareholder approval.

This news release contains forward-looking statements about Mid-State
Bancshares for which Mid-State Bancshares claims the protection of the safe
harbor contained in the Private Securities Reform Act of 1995. Statements
concerning the expected prospects for the effective date of the merger, future
developments or events, and any other guidance on future periods, constitute
forward-looking statements which are subject to a number of risks and
uncertainties which might cause actual results to differ materially from stated
expectations. These factors include, but are not limited to, regulatory reviews
and approvals, competition in the financial services markets for deposits,
loans, and other financial services, retention of business, the ability to
realize various cost saving measures, and general economic conditions. The
forward-looking statements should be considered in the context of these and
other risk factors disclosed in the Mid-State Bancshares's filings with the SEC.

This news release may be deemed to be solicitation material in respect to the
proposed merger of Mid-State Bancshares ("MDST") with Americorp ("AICA.OB")
pursuant to the Agreement to Merge and Plan of Reorganization, dated as of April
9, 2001, by and between Mid-State Bancshares, Mid-State Bank, Americorp and
American Commercial Bank as amended May 24, 2001 (the "Agreement"). Filing of
this news release is being made in connection with Rules 165 and 425 promulgated
by the Securities and Exchange Commission ("SEC").

In connection with the proposed merger, Mid-State Bancshares will file with the
SEC a registration statement on SEC Form S-4. The registration statement will
contain a proxy statement/prospectus which will describe the proposed merger of
Americorp with Mid-State Bancshares as well as the merger of Mid-State Bank with
American Commercial Bank and the proposed terms and conditions of the mergers.
Stockholders are encouraged to read the registration material and proxy
statement/prospectus because these documents will contain important information
about the mergers. A copy of the Agreement, as amended, will be filed in the
near future with the SEC as an exhibit to Mid-State's Form 8-K, a separate
filing from the Form S-4. The registration statement, the Form 8-K and all other
documents filed with the SEC in connection with the transaction will be
available for free when filed, both on SEC's web site (www.sec.gov) or by
contacting James G. Stathos, Executive Vice President at Mid-State Bank, P. O.
Box 580, Arroyo Grande, California. Telephone requests should be directed to
Mid-State Bank at (805) 473-6829.

For more information about Mid-State Bank's products and services, call us at
800/473-7788 or 805/473-7788, E-MAIL US, or visit any of our Central Coast
LOCATIONS.