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                                 EXHIBIT (3)(d)

                          AGREEMENT AND PLAN OF MERGER

    This AGREEMENT AND PLAN OF MERGER ("Plan of Merger") made and entered
into as of the 28th day of December, 2001, by and between National Bancshares
Corporation of Texas, a Texas corporation ("NBT"), and International
Bancshares Corporation, a Texas corporation ("IBC"), being sometimes
hereinafter together referred to as the "Constituent Corporations."

                                  WITNESSETH

    WHEREAS, IBC is a corporation duly organized and existing under the laws
of the State of Texas;

    WHEREAS, NBT is a corporation duly organized and existing under the laws
of the State of Texas, and having authorized capital stock consisting of
100,000,000 shares of common stock, par value $0.001 per share (the "NBT
Common Stock"), and 20,000,000 shares of preferred stock, par value $.01 per
share, of which 1,000 shares of NBT Common Stock are outstanding and owned by
IBC;

    WHEREAS, the Board of Directors of each of the Constituent Corporations
deems it advisable for the general welfare and to the benefit of such
corporations and their respective shareholders that NBT merge with and into
IBC pursuant to Articles 5.01 ET SEQ. of the Texas Business Corporation Act
(the "TBCA");

    WHEREAS, the respective Boards of Directors of the Constituent
Corporations and the sole shareholder of NBT have, in accordance with the
TBCA, by resolutions duly adopted, approved this Plan of Merger and directed
that it be executed by the undersigned officers; and

    WHEREAS, it is the intention of the Constituent Corporations that the
Merger (as hereinafter defined) shall be a tax-free reorganization pursuant
to the provisions of the Internal Revenue Code of 1986, as amended;

    NOW, THEREFORE, in consideration of the premises and the mutual
agreements herein contained, the parties hereby agree, in accordance with the
applicable provisions of the laws of the State of Texas, that the Constituent
Corporations shall be merged into a single corporation, to-wit: IBC, a Texas
corporation, one of the Constituent Corporations, which shall be the
corporation surviving the merger (said corporation hereafter being sometimes
called the "Surviving Corporation"), and the terms and conditions of the
merger hereby agreed upon (hereafter called the "Merger") which the parties
covenant to observe, keep and perform, and the mode of carrying the same into
effect shall be as hereafter set forth:

                                    ARTICLE I

                                 EFFECTIVE DATE

    This Plan of Merger has been approved by the sole shareholder of NBT as
provided by the TBCA.  If this Plan of Merger is not terminated and abandoned
pursuant to the provisions of Article VII hereof, Articles of Merger shall be
filed with the Secretary of State of Texas.  The Merger shall be effective at
6:00 p.m., Central Time, on December 31, 2001 (the "Effective Date").  On the
Effective Date, the separate existence of NBT shall cease and NBT shall be
merged into the Surviving Corporation.

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                                   ARTICLE II

                     CERTIFICATE OF INCORPORATION; BY-LAWS;
                             DIRECTORS AND OFFICERS

    The Articles of Incorporation of IBC shall continue unchanged after the
Merger until changed or amended as provided by law.

    The By-Laws of IBC shall continue unchanged after the Merger until
changed or amended as provided by law.

    The directors and officers of IBC immediately prior to the Effective Date
shall constitute the directors and officers of the Surviving Corporation
immediately following the Effective Date.  Such officers and directors of IBC
shall hold their positions until their resignation or removal or the election
or appointment of their successors in the manner provided by the Articles of
Incorporation and By-Laws of the Surviving Corporation and applicable law.

                                   ARTICLE III

                        CONVERSION OF SHARES IN THE MERGER

    The mode of carrying into effect the Merger provided for herein, and the
manner and basis of converting the shares of the Constituent Corporations,
are as follows:

    1.  Each share of NBT Common Stock which shall be issued and outstanding
as of the Effective Date shall be cancelled and retired, all rights in
respect thereof shall cease to exist and no shares of NBT Common Stock,
common stock of IBC or other securities of NBT or IBC shall be issuable with
respect thereto.

    2.  Each share of common stock of IBC which shall be issued and
outstanding as of the Effective Date shall remain issued and outstanding.

                                   ARTICLE IV

                              EFFECT OF THE MERGER

    On the Effective Date, the separate existence of each Constituent
Corporation (other than the Surviving Corporation) shall cease, except that
whenever a conveyance, assignment, transfer, deed, or other instrument or act
is necessary to vest property or rights in the Surviving Corporation, the
officers, or other authorized representative of the respective Constituent
Corporations shall execute, acknowledge, and deliver such instruments and do
such acts.  For these purposes, the existence of the Constituent Corporations
and the authority of their respective officers, directors, or other
authorized representatives is continued notwithstanding the Merger.  The
Surviving Corporation shall possess all assets and property of every
description, and every interest in the assets and property, wherever located,
and the rights, privileges, immunities, powers, franchises, and authority, of
a public as well as of a private nature, of each Constituent Corporation, and
all obligations belonging to or due to each Constituent Corporation, all of
which are vested in the Surviving Corporation without further act or deed.
Title to any real estate or any interest in the real estate vested in any
Constituent Corporation shall not revert or in any way be impaired by reason
of such  merger or consolidation.  The Surviving Corporation is liable for
all the obligations of each Constituent Corporation, including liability to
dissenting

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shareholders.  Any claim existing or any action or proceeding pending by or
against any Constituent Corporation may be prosecuted to judgment, with right
or appeal, as if the Merger had not taken place, or the Surviving Corporation
may be substituted in its place.  All rights of creditors of each Constituent
Corporation are preserved unimpaired, and all liens upon the property of any
Constituent Corporation are preserved unimpaired, on only the property
affected by such liens immediately prior to the Effective Date.

                                    ARTICLE V

                                ACCOUNTING MATTERS

    The assets and liabilities of the Constituent Corporations, as of the
Effective Date of the Merger, shall be taken upon the books of the Surviving
Corporation at the amounts at which they shall be carried at that time on the
books of the respective Constituent Corporations, subject to such adjustments
or eliminations of inter-company items as may be appropriate in giving effect
to the Merger.  The amount of the capital surplus and earned surplus
accounts, if any, of the Surviving Corporation after the Merger shall be
determined by the Board of Directors of the Surviving Corporation in
accordance with the laws of the State of Texas and with generally accepted
accounting principles.

                                   ARTICLE VI

                            APPROVAL OF SHAREHOLDERS

    This Plan of Merger has been approved by the sole shareholder of NBT as
provided by the TBCA.

                                   ARTICLE VII

                                   ABANDONMENT

    This Plan of Merger may be abandoned at any time notwithstanding
favorable action on the Merger by the sole shareholder of NBT by the Board of
Directors of IBC and NBT evidenced by appropriate resolutions.  In the event
the Plan of Merger is terminated after filing of the Articles of Merger with
the Secretary of State of the State of Texas but before the Effective Date, a
Certificate of Termination of Merger must be filed with the Secretary of
State of the State of Texas.  In the event of the termination and abandonment
of this Plan of Merger and the Merger pursuant to this Article VII, this Plan
of Merger shall become void and have no effect, without any liability on the
part of either of the Constituent Corporations or their shareholders or
directors or officers in respect thereof.

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                                  ARTICLE VIII

                                   AMENDMENT

    IBC and NBT, by mutual consent of their respective Boards of Directors,
may amend this Plan of Merger in such manner as may be agreed upon by them in
writing at any time but not later than the Effective Date; provided, however,
no such amendment shall be made which shall affect the rights of the
shareholders of IBC or NBT in a manner which, in the judgment of the Boards
of Directors of IBC or NBT, respectively, is materially adverse to such
shareholders, or as otherwise provided by the TBCA, without the further
approval of such shareholders.

                                   ARTICLE IX

                               FURTHER ASSURANCES

    If at any time the Surviving Corporation shall consider or be advised
that any further assignment or assurance in law or other action is necessary
or desirable to vest, perfect, or confirm, of record or otherwise, in the
Surviving Corporation, the title to any property or rights of NBT acquired or
to be acquired by or as a result of the Merger, the proper officers and
directors of the Surviving Corporation shall be and they hereby are severally
and fully authorized to execute and deliver such proper deeds, assignments
and assurances in law, and take such other action as may be necessary or
proper in the name of IBC or NBT to vest, perfect or confirm title to such
property or rights in the Surviving Corporation and otherwise carry out the
purposes of this Plan of Merger.

                                   ARTICLE X

                                  COUNTERPARTS

    This Plan of Merger may be executed in multiple counterparts, each of
which when so executed shall be deemed to be an original, and such
counterparts taken together shall constitute but one and the same instrument.

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    IN WITNESS WHEREOF, IBC and NBT, pursuant to the approval and authority
duly given by resolutions adopted by their respective Boards of Directors,
have each caused this Plan of Merger to be executed by its duly authorized
officers, all as of the day and year first above written.

                                    INTERNATIONAL BANCSHARES CORPORATION,
                                    a Texas corporation


                                    By: /s/ DENNIS E. NIXON
                                       --------------------------------------
                                            Dennis E. Nixon,
                                            Chairman of the Board and President


                                    NATIONAL BANCSHARES CORPORATION
                                    OF TEXAS,
                                    a Texas corporation


                                    By: /s/ DENNIS E. NIXON
                                       --------------------------------------
                                            Dennis E. Nixon,
                                            Chairman of the Board