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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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                                   SCHEDULE TO
                                 (RULE 14d-100)

                  TENDER OFFER STATEMENT UNDER SECTION 14(d)(1)
           OR SECTION 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934

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                    NATIONAL BANCSHARES CORPORATION OF TEXAS
                       (Name of Subject Company (Issuer))

                      INTERNATIONAL BANCSHARES CORPORATION
                              NBC ACQUISITION CORP.
                      (Names of Filing Persons (Offerors))

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                     COMMON STOCK, PAR VALUE $.001 PER SHARE
                         (Title of Class of Securities)

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                                 632-593-505-000
                      (CUSIP Number of Class of Securities)

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                                 DENNIS E. NIXON
                      CHAIRMAN AND CHIEF EXECUTIVE OFFICER
                      INTERNATIONAL BANCSHARES CORPORATION
                             1200 SAN BERNARDO AVE.
                                  LAREDO, TEXAS
                            TELEPHONE: (956) 722-7611
           (Name, address and telephone number of person authorized to
         receive notices and communications on behalf of filing persons)

                                   COPIES TO:

                                CARY PLOTKIN KAVY
                            COX & SMITH INCORPORATED
                            112 E. PECAN, SUITE 1800
                               SAN ANTONIO, TEXAS
                            TELEPHONE: (210) 554-5500

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                           CALCULATION OF FILING FEE:


                                               
================================================================================
       TRANSACTION VALUATION*                          AMOUNT OF FILING FEE
--------------------------------------------------------------------------------
          Not applicable.                                 Not applicable.
================================================================================


*Set forth the amount on which the filing fee is calculated and state how it was
determined.

[ ]  Check the box if any part of the fee is offset as provided by Rule
     0-11(a)(2) and identify the filing with which the offsetting fee was
     previously paid. Identify the previous filing by registration statement
     number, or the Form or Schedule and the date of its filing.

     Amount Previously Paid: .....  N/A     Filing Party: .............     N/A
     Form or Registration No.: ...  N/A     Date Filed: ...............     N/A


[X]  Check the box if the filing relates solely to preliminary communications
     made before the commencement of a tender offer.

     Check the appropriate boxes to designate any transactions to which this
     statement relates:

     [X]  third-party tender offer subject to Rule 14d-1.
     [ ]  issuer tender offer subject to Rule 13e-4.
     [ ]  going-private transaction subject to Rule 13e-3.
     [ ]  amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results
of the tender offer: [ ]

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The description contained herein is neither an offer to purchase nor a
solicitation of an offer to sell shares of National Bancshares Corporation of
Texas. At the time the tender offer is commenced, International Bancshares
Corporation, a Texas corporation, and NBC Acquisition Corp., a Texas corporation
and a wholly owned subsidiary of International Bancshares Corporation, will file
a Tender Offer Statement and National Bancshares Corporation of Texas will file
a Solicitation/Recommendation Statement with respect to the offer. The Tender
Offer Statement (including an offer to purchase, a related letter of transmittal
and other offer documents) and the Solicitation/Recommendation Statement will
contain important information that should be read carefully before any decision
is made with respect to the offer.


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The offer to purchase, the related letter of transmittal and certain other
documents, as well as the Solicitation/Recommendation Statement, will be made
available to all shareholders of National Bancshares Corporation of Texas, at no
expense to them. The Tender Offer Statement (including an offer to purchase, a
related letter of transmittal and other offer documents) and the
Solicitation/Recommendation Statement will also be available at no charge at the
SEC's website at www.sec.gov.



             INTERNATIONAL BANCSHARES CORPORATION AGREES TO ACQUIRE
                    NATIONAL BANCSHARES CORPORATION OF TEXAS


LAREDO, TEXAS, July 31, 2001 - International Bancshares Corporation (NASDAQ:
IBOC) announced today that it has agreed with San Antonio-based National
Bancshares Corporation of Texas (AMEX: NBT) to acquire all of National
Bancshares pursuant to a cash tender offer at $24.75 per share. The Boards of
both companies have approved this transaction.

The acquisition is to be accomplished through a cash tender offer for all of
National Bancshares' common stock at a price of $24.75 per share. Following
completion of the tender offer and necessary approvals, National Bancshares will
be merged with a subsidiary of IBC, and all of the remaining National Bancshares
shareholders would receive the same price paid in the tender offer in cash. The
tender offer and the merger are subject to regulatory approvals and to other
customary conditions, including the tender of at least two-thirds of the shares
of National Bancshares.

Commenting on today's announcement, Dennis E. Nixon, Chairman and Chief
Executive Officer of IBC, said: "We are delighted with the transaction because
it will add strength to IBC's existing markets along with broadening its
domestic and international deposit base as well as giving IBC the opportunity to
gain new operational efficiencies based on a larger volume of business."

"This transaction presents a good opportunity to grow National Bancshares'
operations while providing shareholders substantial value," said Marvin E.
Melson, National Bancshares' President and CEO.

International Bancshares Corporation is a multi-bank holding company with $6.1
billion in assets. Headquartered in Laredo, Texas, IBC has more than 100
facilities serving 30 communities, including Houston, San Antonio, Corpus
Christi, McAllen, Brownsville, Port Lavaca, Zapata and other communities
throughout the Rio Grande Valley and the Texas Gulf Coast. Founded in 1979, IBC
has focused on providing commercial financial services to small and medium-sized
businesses in Texas and internationally, primarily in Mexico.


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National Bancshares Corporation of Texas is a bank holding company incorporated
in 1971. National Bancshares conducts its banking operations through 12
facilities located in South and Central Texas. At March 31, 2001, National
Bancshares had assets of $606.3 million and total deposits of $534.5 million.

Sandler O'Neill & Partners, L.P. acted as financial adviser for IBC in this
transaction, and Keefe, Bruyette & Woods, Inc. acted as financial adviser to
National Bancshares.

NOTICE TO READ TENDER OFFER DOCUMENTS:

THE DESCRIPTION CONTAINED HEREIN IS NEITHER AN OFFER TO PURCHASE NOR A
SOLICITATION OF AN OFFER TO SELL SHARES OF NATIONAL BANCSHARES. A TENDER OFFER
STATEMENT ON SCHEDULE TO WILL BE FILED BY IBC AND A SOLICITATION/RECOMMENDATION
STATEMENT ON SCHEDULE 14D-9 WILL BE FILED BY NATIONAL BANCSHARES WITH THE
SECURITIES AND EXCHANGE COMMISSION (SEC). YOU ARE URGED TO READ THE TENDER OFFER
STATEMENT, THE SOLICITATION/RECOMMENDATION STATEMENT AND ANY OTHER RELEVANT
DOCUMENTS TO BE FILED WITH THE SEC. THE TENDER OFFER STATEMENT, THE
SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9 AND OTHER DOCUMENTS
FILED WITH THE SEC WILL CONTAIN IMPORTANT INFORMATION THAT YOU SHOULD CONSIDER
BEFORE MAKING ANY DECISION REGARDING THE TENDER OFFER AND RELATED TRANSACTIONS.
YOU MAY OBTAIN A FREE COPY OF THE TENDER OFFER STATEMENT AND OTHER DOCUMENTS
FILED BY IBC AND NATIONAL BANCSHARES WITH THE SEC AT THE SEC'S WEB SITE AT
WWW.SEC.GOV. THE TENDER OFFER STATEMENT AND OTHER DOCUMENTS TO BE FILED WITH THE
SEC BY IBC WILL BE AVAILABLE FREE OF CHARGE FROM IBC BY DIRECTING A REQUEST TO
INTERNATIONAL BANCSHARES CORPORATION, 1200 SAN BERNARDO AVE., LAREDO, TEXAS
78040, ATTN: JONATHAN A. NIXON. IN ADDITION, THE SOLICITATION/RECOMMENDATION
STATEMENT ON SCHEDULE 14D-9 AND OTHER DOCUMENTS TO BE FILED WITH THE SEC BY
NATIONAL BANCSHARES MAY BE OBTAINED FREE OF CHARGE FROM NATIONAL BANCSHARES BY
DIRECTING A REQUEST TO NATIONAL BANCSHARES CORPORATION OF TEXAS, 12400 HIGHWAY
281 NORTH, SAN ANTONIO, TEXAS 78216, ATTN: MORRIS D. WEISS.

CAUTIONARY NOTE REGARDING FORWARD LOOKING STATEMENTS

This press release contains "forward-looking statements" as that term is defined
in the Private Securities Litigation Reform Act of 1995. Such forward-looking
statements are not guarantees of future performance. Actual results may differ
materially from the forward-looking statements as a result of a number of risks
and uncertainties, many of which are outside our control, including but not
limited to the risks described in the documents that each of IBC and National
Bancshares has filed with the SEC. Investors and security holders are urged to
read those documents at the SEC's web site at www.sec.gov. Those documents may
also be obtained free of charge from IBC.


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                                  * * * * * * *

For more information, contact:

                  Dennis E. Nixon
                  Chairman and CEO
                  International Bancshares Corporation
                  (956) 722-7611


                  Marvin E. Melson
                  President and CEO
                  National Bancshares Corporation of Texas
                  (210) 403-4211