Exhibit 10.1

NON-COMPETITION, NON-SOLICITATION

AND CONFIDENTIALITY AGREEMENT

THIS NON-COMPETITION, NON-SOLICITATION AND CONFIDENTIALITY AGREEMENT (this
“Agreement”), which is effective as of January 31, 2007 (the “Effective Date”),
is by and among L. Don Stricklin, an individual who resides in La Grange, Texas
(the “Undersigned”), Texas United Bancshares, Inc., a Texas corporation (the
“Company”), and Prosperity Bancshares, Inc., a Texas corporation (“Prosperity
Bancshares”). Prosperity Bancshares and Prosperity Bank, a Texas banking
association are collectively referred to herein as “Prosperity.”

WHEREAS, this Agreement is being entered into in connection with the Agreement
and Plan of Reorganization, dated as of July 18, 2006, as amended, by and
between Prosperity Bancshares and the Company (the “Merger Agreement”), pursuant
to which the Company will merge with and into Prosperity Bancshares, with
Prosperity Bancshares as the surviving entity (the “Merger”); and

WHEREAS, Prosperity Bancshares has required as a condition to consummation of
the Merger that the Undersigned execute and deliver a non-competition and
non-solicitation agreement for the benefit of Prosperity and the Undersigned’s
agreement to and compliance with the provisions of this Agreement are a material
factor, material inducement and material condition to Prosperity’s participation
in the transactions contemplated by the Merger Agreement; and

WHEREAS, Prosperity has agreed to pay the Undersigned $65,000 per year for two
years in consideration for the Undersigned executing and delivering this
Agreement; and

WHEREAS, the Undersigned will receive pecuniary and other benefits as a result
of the Merger; and

WHEREAS, the Undersigned, as a director, executive officer and/or shareholder of
the Company, as the case may be, has had access to certain Confidential
Information (as hereinafter defined), including, without limitation, information
concerning the Company’s business and the relationships between the Company, its
subsidiaries and their customers, and the Undersigned will continue to have
access to Confidential Information and may have access to new Confidential
Information of the Company; and

WHEREAS, the Undersigned recognizes that Prosperity Bancshares would not have
entered into the Merger Agreement without the Undersigned agreeing to the terms
and conditions of this Agreement; and

WHEREAS, any capitalized term not defined herein shall have the meaning set
forth in the Merger Agreement;

 

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NOW, THEREFORE, in consideration of the good and valuable consideration
contained herein and in the Merger Agreement, the receipt and sufficiency of
which are hereby acknowledged, the Undersigned hereby agrees as follows:

1. The Undersigned agrees that he will not, at any time after the Effective Date
and through and including the Closing Date make any unauthorized disclosure,
directly or indirectly, of any Confidential Information of the Company or third
parties, or make any use thereof, directly or indirectly. The Undersigned
further agrees that he will not, at any time after the Effective Date make any
unauthorized disclosure, directly or indirectly, of any Confidential Information
of Prosperity or third parties, or make any use thereof, directly or indirectly
and that he shall deliver promptly to Prosperity at any time after the Effective
Time of the Merger, at its reasonable request, without retaining any copies, all
documents and other material in the Undersigned’s possession at that time
relating, directly or indirectly, to any Confidential Information or other
information of the Company, or Confidential Information or other information
regarding third parties, learned in such person’s position as a director,
officer or shareholder of the Company.

For purposes of this Agreement, “Confidential Information” means and includes
Prosperity’s and/or the Company’s confidential and/or proprietary information
and/or trade secrets, including those of their respective subsidiaries,
including Prosperity Bank, Gateway National Bank, GNB Financial, n.a., Northwest
Bank and State Bank, that have been and/or will be developed or used and that
cannot be obtained readily by third parties from outside sources. Confidential
Information includes, but is not limited to, the following: information
regarding past, current and prospective customers and investors and business
affiliates, employees, contractors, and the industry not generally known to the
public; strategies, methods, books, records, and documents; technical
information concerning products, equipment, services, and processes; procurement
procedures, pricing, and pricing techniques, including contact names, services
provided, pricing, type and amount of services used; financial data; pricing
strategies and price curves; positions; plans or strategies for expansion or
acquisitions; budgets; research; financial and sales data; trading methodologies
and terms; communications information; evaluations, opinions and interpretations
of information and data; marketing and merchandising techniques; electronic
databases; models; specifications; computer programs; contracts; bids or
proposals; technologies and methods; training methods and processes;
organizational structure; personnel information; payments or rates paid to
consultants or other service providers; and other such confidential or
proprietary information. The term “Confidential Information” does not include
any information that (i) at the time of disclosure or thereafter is generally
available to and known to the public, other than by a breach of this Agreement
by the disclosing party, (ii) was available to the disclosing party on a
non-confidential basis from a source other than the non-disclosing party or
(iii) was independently acquired or developed without violating any obligations
of this Agreement. The Undersigned acknowledges that the Company’s and
Prosperity’s business is highly competitive, that this Confidential Information
constitutes a valuable, special and unique asset to be acquired by Prosperity in
the Merger and that protection of such Confidential Information against
unauthorized disclosure and use is of critical importance to the Company and
Prosperity.

 

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2. The Undersigned agrees that, for the period (the “Non-Competition Period”)
beginning on the Effective Date and through the second anniversary of the
Closing Date, the Undersigned will not, in any capacity, directly or indirectly:

 

  a) compete or engage, anywhere in the geographic area comprised of the fifty
(50) mile radius surrounding any banking center of the Company or Prosperity or
any other banking center operated or owned directly or indirectly by Prosperity
(the “Market Area”), in a business similar to that of the Company or Prosperity,
or compete or engage in that type of business which the Company or Prosperity
has plans to engage in, or any business which the Company or Prosperity has
engaged in during the preceding twelve (12) month period if within the
twenty-four (24) months before the Closing Date, the Undersigned had access or
potential access to Confidential Information regarding the proposed plans or the
business in which the Company or Prosperity engaged or planned to engage; or

 

  b) take any action to invest in, own, manage, operate, control, participate
in, be employed or engaged by or be connected in any manner with any
partnership, corporation or other business or entity engaging in a business
similar to that of Prosperity or the Company anywhere within the Market Area.
Notwithstanding the foregoing, the Undersigned is permitted hereunder to own,
directly or indirectly, up to one percent (1%) of the issued and outstanding
securities of any publicly traded financial institution conducting business in
the Market Area; or

 

  c) call on, service or solicit competing business from customers or
prospective customers of the Company or Prosperity or their respective
Subsidiaries.

3. The Undersigned agrees that, other than as set forth in this Section 3, for
the period (the “Non-Solicitation Period”) beginning on the Effective Date and
through the fifth anniversary of the Closing Date, the Undersigned will not, in
any capacity, directly or indirectly, call on, solicit, or hire any current or
past employee of the Company or any of its subsidiaries and/or of Prosperity or
any of its subsidiaries, and will not assist any other person or entity in such
activities. Additionally, the Undersigned agrees that for the Non-Solicitation
Period he will not, in any capacity, directly or indirectly, induce any employee
of the Company or any of its subsidiaries and/or of Prosperity or any of its
subsidiaries to terminate employment from the Company or any of its subsidiaries
or from Prosperity or any of its subsidiaries, and will not assist any other
person or entity in such activities. The Undersigned further agrees and
acknowledges that he may be permitted to call on, solicit, or hire any such
employee who is no longer employed by the Company or any of its subsidiaries or
by Prosperity or any of its subsidiaries; provided the Undersigned receives
prior written authorization from Prosperity before engaging in any such action.
Provided, however, that after the second anniversary of the Closing Date, if
Prosperity shall not be the surviving corporation in a merger then the
Non-Solicitation Period shall end.

4. The Undersigned acknowledges that the restrictions imposed by this Agreement
are legitimate, reasonable and necessary to protect Prosperity’s proposed
acquisition of the

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Company and the goodwill thereof. The Undersigned acknowledges that the scope
and duration of the restrictions contained herein are reasonable in light of the
time that the Undersigned has been engaged in the business of the Company and
the Undersigned’s relationship with the customers of the Company. The
Undersigned further acknowledges that the restrictions contained herein are not
burdensome to the Undersigned in light of the consideration to be paid therefor
and the other opportunities that remain open to the Undersigned. Moreover, the
Undersigned acknowledges that he has and will have other means available to him
for the pursuit of his livelihood after the Effective Date.

5. The Undersigned acknowledges and agrees that the breach of any of the
covenants made by the Undersigned in this Agreement would cause irreparable
injury to Prosperity, which could not sufficiently be remedied by monetary
damages; and, therefore, that Prosperity shall be entitled to obtain such
equitable relief as declaratory judgments; temporary, preliminary and permanent
injunctions, without posting of any bond, and order of specific performance to
enforce those covenants or to prohibit any act or omission that constitutes a
breach thereof. If Prosperity must bring suit to enforce this Agreement, the
prevailing party shall be entitled to recover its attorneys’ fees and costs
related thereto.

6. In the event that Prosperity shall file a lawsuit in any court of competent
jurisdiction alleging a breach of the non-disclosure, non-competition or
non-solicitation provisions of this Agreement by the Undersigned, then any time
period set forth in this Agreement including the time period set forth in
Sections 2 and 3 above, shall be deemed tolled as of the time such lawsuit is
filed and shall remain tolled until such dispute finally is resolved either by
written settlement agreement resolving all claims raised in such lawsuit or by
entry of a final judgment in such lawsuit and the final resolution of any
post-judgment appellate proceedings.

7. In consideration for the above obligations of the Undersigned, in addition to
those matters set forth in the Recitals to this Agreement, the Company agrees to
provide the Undersigned with immediate access to new Confidential Information
relating to the Company’s business, which will become Prosperity’s business
after the Closing Date. The Undersigned also will have immediate access to, or
knowledge of, new Confidential Information of third parties, such as actual and
potential customers, suppliers, partners, joint venturers, investors, financing
sources, etc., of the Company and of Prosperity after the Closing Date. In
addition, in exchange for the Undersigned’s promises in Sections 2 and 3 of this
Agreement, Prosperity will pay the Undersigned a payment of $65,000 per year for
two years, less applicable withholding taxes, payable in equal installments on a
semi-monthly basis beginning with the first installment to be made on the
Closing Date and each subsequent installment to be made on the first and
fifteenth day of each month following the Closing Date (or as soon as
administratively practicable thereafter). Notwithstanding any provision of this
Agreement to the contrary, no payment or benefit will be provided under this
Section 7 until the earliest of (i) the date which is 6 months after the date of
the Undersigned’s termination of employment, or (ii) the date of Undersigned’s
death. Payments to which the Undersigned would otherwise be entitled during the
6-month period described above will be accumulated and paid in a lump sum on the
first day of the seventh month after the date of the Undersigned’s termination
of employment. In addition, if any provision of this Agreement (or of any award
of compensation) would cause the Undersigned to incur any additional tax or
interest under Section 409A of the Code or any regulations or

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Treasury guidance promulgated thereunder, the Undersigned shall reform such
provision; provided that Prosperity shall (A) maintain, to the maximum extent
practicable, the original intent of the applicable provision without violating
the provisions of Section 409A of the Code and (B) notify and consult with the
Undersigned regarding such amendments or modifications prior to the effective
date of any such change.

8. This Agreement exclusively shall be governed by and construed in accordance
with the laws of the State of Texas. Exclusive venue of any dispute relating to
this Agreement shall be, and is convenient in federal district court or in the
district courts of Harris County, Texas. The Undersigned agrees that he will not
contest venue in Harris County, Texas or the application of Texas laws to any
dispute relating to this Agreement or the Undersigned’s employment with the
Company and/or Prosperity.

9. This Agreement shall not be amended, modified, or altered in any manner
except in writing signed by both parties.

10. If any provision of this Agreement is held by a court of competent
jurisdiction to be invalid, void, or unenforceable, the remaining provisions
shall remain in full force and effect, as if this Agreement has been executed
without any such invalid provisions having been included. Such invalid provision
shall be reformed in a manner that is both (i) legal and enforceable, and
(ii) most closely represents the parties’ original intent.

11. EACH OF THE PARTIES HERETO HEREBY WAIVES ITS RESPECTIVE RIGHTS TO A JURY
TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING HEREUNDER OR ANY
DEALINGS BETWEEN THEM RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT OR THE
RELATIONSHIP THAT IS BEING ESTABLISHED. THE SCOPE OF THIS WAIVER IS INTENDED TO
BE ALL-ENCOMPASSING OF ANY AND ALL DISPUTES THAT MAY BE FILED IN ANY COURT AND
THAT RELATE TO THE SUBJECT MATTER OF THIS AGREEMENT, INCLUDING CONTRACT CLAIMS,
TORT CLAIMS, BREACH OF DUTY CLAIMS AND ALL OTHER COMMON LAW AND STATUTORY
CLAIMS. EACH PARTY HERETO ACKNOWLEDGES THAT THIS WAIVER IS A MATERIAL INDUCEMENT
TO ENTER INTO A BUSINESS RELATIONSHIP THAT EACH HAS ALREADY RELIED ON THIS
WAIVER IN ENTERING INTO THIS AGREEMENT, AND THAT EACH WILL CONTINUE TO RELY ON
THIS WAIVER IN ITS RELATED FUTURE DEALINGS. EACH PARTY HERETO FURTHER WARRANTS
AND REPRESENTS THAT IT HAS REVIEWED THIS WAIVER WITH ITS LEGAL COUNSEL AND THAT
IT KNOWINGLY AND VOLUNTARILY WAIVES ITS JURY TRIAL RIGHTS FOLLOWING CONSULTATION
WITH LEGAL COUNSEL. THIS WAIVER IS IRREVOCABLE, MEANING THAT IT MAY NOT BE
MODIFIED EITHER ORALLY OR IN WRITING (OTHER THAN BY A MUTUAL WRITTEN WAIVER
SPECIFICALLY REFERRING TO THIS SECTION AND EXECUTED BY EACH OF THE PARTIES
HERETO), AND THIS WAIVER SHALL APPLY TO ANY SUBSEQUENT AMENDMENTS, SUPPLEMENTS
OR MODIFICATIONS HERETO. IN THE EVENT OF LITIGATION, THIS AGREEMENT MAY BE FILED
AS A WRITTEN CONSENT TO A TRIAL BY THE COURT.

 

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12. This Agreement sets forth the entire agreement of the parties relating to
the subject matter hereof, and supersede any and all other agreements or
understandings, written or oral, between Prosperity and the Undersigned. The
Undersigned has no oral representations, understandings or agreements with
Prosperity or any of its officers, directors or representatives covering the
same subject matter as this Agreement. This Agreement is the final, complete and
exclusive statement and expression of the agreement among the parties hereto and
of all the terms of this Agreement, and it cannot be varied, contradicted or
supplemented by evidence of any prior or contemporaneous oral or written
agreements.

13. This Agreement shall be binding upon and shall inure to the benefit of
Prosperity and its successors and assigns, including, without limitation, any
successor by merger, consolidation or stock purchase of Prosperity and any
entity or person that acquires all or substantially all of the assets of
Prosperity.

[Signature Page Follows]

 

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IN WITNESS WHEREOF, the Undersigned has caused this Agreement to be duly
executed as of the date first written above.

 

UNDERSIGNED /s/    L. Don Stricklin L. Don Stricklin

 

TEXAS UNITED BANCSHARES, INC. By:   /s/    Jeff A. Wilkinson Name:   Jeff A.
Wilkinson Title:   Chief Financial Officer and Executive Vice President

 

PROSPERITY BANCSHARES, INC. By:   /s/    David Zalman Name:   David Zalman
Title:   Chairman of the Board and Chief Executive Officer