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                                             Filed by Southside Bancshares Corp.
         Filed pursuant to Rule 425 under the Securities Act of 1933, as amended
    and deemed filed under Rule 14a-6 of the Securities Exchange Act of 1934, as
                                                                         amended

                                     Subject Company: Southside Bancshares Corp.
                                                   Commission File No. 333-63212

To Shareholders of Southside Bancshares Corp.:

Enclosed is a new blue proxy card which you should use in voting upon (1) the
election of directors to Southside's board of directors and (2) the proposed
merger of Allegiant Bancorp and Southside Bancshares, both as described in the
joint proxy statement/prospectus dated August 1, 2001 which you previously
received.

You are receiving this blue proxy card because the white proxy card which
originally accompanied your joint proxy statement/prospectus did not clearly
indicate where you should sign your name. This blue proxy card contains a
signature line for you to sign your name.

If you already voted on the white proxy card AND SIGNED YOUR NAME, you may
disregard this blue proxy card. If you already voted on the white proxy card but
failed to sign your name or did not yet return the white proxy card, we ask that
you sign, date and return this blue proxy card as soon as possible.

Information about the proxy card and the voting process is set forth in the
joint proxy statement/prospectus. If you have any further questions, please
contact Joseph W. Pope at (314) 416-4111. We appreciate your cooperation.


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               - FOLD HERE AND RETURN IN THE ENCLOSED ENVELOPE -


                           SOUTHSIDE BANCSHARES CORP.
                               3606 GRAVOIS AVENUE
                            ST. LOUIS, MISSOURI 63116

                      THIS PROXY IS SOLICITED ON BEHALF OF
              THE BOARD OF DIRECTORS OF SOUTHSIDE BANCSHARES CORP.

         The undersigned hereby appoints Mitchell P. Baden and Laurie A.
Pennycook, and each of them, with or without the other, attorneys and proxies,
with full power of substitution and revocation, to vote all of the shares of
common stock of Southside Bancshares Corp. which the undersigned is entitled to
vote at the annual meeting of shareholders of the company to be held at South
Side National Bank's Telegraph Road facility, located at 4111 Telegraph Road,
St. Louis County, Missouri, on Wednesday, September 12, 2001, at 3:00 p.m., and
at any adjournments thereof: (1) as hereinafter specified upon the proposals
listed below and as more particularly described in the company's joint proxy
statement/prospectus, receipt of which is hereby acknowledged; and (2) in their
discretion upon such other matters as may properly come before the annual
meeting of shareholders.

A VOTE FOR THE FOLLOWING PROPOSAL (AS DESCRIBED IN GREATER DETAIL IN THE JOINT
PROXY STATEMENT/PROSPECTUS) IS RECOMMENDED BY A MAJORITY OF THE BOARD OF
DIRECTORS.

     1.   Election of directors: Douglas P. Helein, Earle J. Kennedy, Jr.,
          Daniel J. Queen and Steven C. Roberts.

          [ ]  FOR all nominees listed (except as marked to the contrary).
          [ ]  WITHHOLD AUTHORITY to vote for all nominees listed.
          [ ]  WITHHOLD AUTHORITY to vote for
                                             ----------------------------------.

A VOTE FOR THE FOLLOWING PROPOSAL (AS DESCRIBED IN GREATER DETAIL IN THE JOINT
PROXY STATEMENT/PROSPECTUS) IS UNANIMOUSLY RECOMMENDED BY THE BOARD OF
DIRECTORS.

     2.   Approval of the plan of merger between the company and Allegiant
          Bancorp, Inc. set forth in the merger agreement between the company
          and Allegiant Bancorp, Inc. and the transactions contemplated by that
          agreement

          [ ] FOR                    [ ] AGAINST                    [ ] ABSTAIN

   (YOU ARE REQUESTED TO COMPLETE, DATE, SIGN, AND RETURN THIS PROXY PROMPTLY)

                             SOUTHSIDE SHAREHOLDERS

This proxy, when properly executed, will be voted in the manner directed herein
by the undersigned shareholder. If no direction is made, the proxy will be voted
FOR Proposals 1 and 2. If any other matters properly come before the annual
meeting, the proxy holders will vote the shares of common stock represented by
your proxy in their discretion.

TO ASSURE THAT YOUR SHARES ARE REPRESENTED AT THE ANNUAL MEETING, PLEASE SIGN,
DATE AND PROMPTLY RETURN THIS SOUTHSIDE PROXY CARD IN THE ENVELOPE PROVIDED. IF
YOU PLAN TO ATTEND THE ANNUAL MEETING AND ARE A SHAREHOLDER OF RECORD, PLEASE
MARK THE PROXY CARD APPROPRIATELY AND RETURN IT. HOWEVER, IF YOUR SHARES ARE NOT
REGISTERED IN YOUR OWN NAME, PLEASE ADVISE THE SHAREHOLDER OF RECORD (YOUR BANK,
BROKER, ETC.) THAT YOU WISH TO ATTEND. THAT FIRM MUST PROVIDE YOU WITH EVIDENCE
OF YOUR OWNERSHIP WHICH WILL ENABLE YOU TO GAIN ADMITTANCE TO THE ANNUAL
MEETING.

                                    Dated                        , 2001
                                          -----------------------
                                    Signature:
                                               ---------------------------------
                                    Signature:
                                               ---------------------------------
                                    Print Name(s):
                                                   -----------------------------

                                    --------------------------------------------

                                    IMPORTANT: Please date this proxy and sign
                                    exactly as your name(s) appears thereon. If
                                    stock is held jointly, signature should
                                    include both names. Executors,
                                    administrators, trustees, guardians,
                                    corporate officers and others signing in a
                                    representative capacity should so indicate.

                                    PROXY MUST BE RETURNED BY SEPTEMBER 12, 2001

                                    [ ] Please check box if you plan to attend
                                    the annual meeting.