<PAGE>   1
                                EXHIBIT 10.12

Form of Shareholder's Agreement between Registrant and certain executive
officers and between Registrant and certain employees.

The Following  Form  Agreement  was entered into between the  Registrant  and
Messrs.  Thompson,  Waner,  Rastocan, Harvey, and Witt.  Mr. Rastocan also
subscribed to 8,126.9269 shares at $12.17 per share.(See Item 5 above).


                             SHAREHOLDERS' AGREEMENT

         THIS SHAREHOLDERS' AGREEMENT is made as of October 20, 1997, among
PENDA CORPORATION, a Florida corporation (the "Company"), the Investors (as
hereinafter defined) and XXXX (the "Executive").

                             Preliminary Statements:

         A. The Investors are the holders of 412,871 issued and outstanding
shares of the Common Stock of the Company.

         B. This Agreement is being entered into in connection with (i) the
Stock Option Substitution Agreement, dated as of October 20, 1997, between the
Executive and the Company (the "Stock Option Substitution Agreement"), and (ii)
the Penda Corporation Management Stock Option Plan and Agreement for XXXX (the
"Stock Option Plan").

         C. The Investors and the Executive believe that it would be in the best
interest of the Company to place certain restrictions upon the right of transfer
of the Executive Stock.

         D. The directors of the Company, having considered the provisions of
this Agreement, have resolved that in their opinion the restrictions upon the
transfer of the Executive Stock and the establishment of rights and obligations
upon the occurrence of certain events, all as hereinafter set forth, are in the
best interest of the Company and its shareholders.

                                   Agreement:

         NOW THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereto agree as follows:

         1.       Interpretation of this Agreement.

                  (a)      Terms  Defined.  As used herein,  the following
terms when used in this  Agreement have the meanings set forth below:

                  "Affiliate" has the meaning set forth in Rule 12b-2 of the
regulations promulgated under the Securities Exchange Act of 1934, as amended.

                  "Agreement" means this Shareholders' Agreement and all
exhibits and schedules hereto.

                  "Approved Sale" shall have the meaning given to it in ss.4(a)
hereof.

                  "Common Stock" means the Company's Common Stock, par value
$.01 per share.

                  "Company" shall have the meaning given to it in the first
sentence of this Agreement.



                                       71

<PAGE>   2
                  "Company Sale" means (i) the sale of all, or substantially
all, of the Company's consolidated assets in any single transaction or series of
related transactions; (ii) the sale or issuance, or series of related sales or
issuances, of Common Stock in any single transaction or series of related
transactions which results in any Person or group of affiliated Persons (other
than the holders of Common Stock as of the date of this Agreement and affiliates
of such holders) owning more than 66% of the Common Stock outstanding
immediately prior to such sale or issuance or such series of sales and/or
issuances; (iii) the consummation of a public sale of Common Stock pursuant to a
registration statement which has become effective under the Securities Act, the
net proceeds of which sale to the Company are at least $20 million; or (iv) any
merger or consolidation of the Company with or into another corporation
(regardless of which entity is the surviving corporation) if, after giving
effect to such merger or consolidation the holders of the Company's voting
securities (on a fully-diluted basis) immediately prior to the merger or
consolidation own voting securities of the surviving or resulting corporation
representing less than a majority of the ordinary voting power to elect
directors of the surviving or resulting corporation (on a fully-diluted basis).

                  "Executive" shall have the meaning given to it in the first
sentence of this Agreement.

                  "Executive Stock" means (i) all Common Stock now owned
beneficially or of record by the Executive (including, without limitation, all
Common Stock held of record by Robert W. Baird & Co. Incorporated, Trustee for
the benefit of the Executive's Individual Retirement Account), (ii) all Common
Stock hereafter acquired by the Executive (including any shares acquired by the
Executive upon the exercise of options granted to the Executive under the Stock
Option Plan or upon the exercise of "Surviving Options", as such term is defined
in the Stock Option Substitution Agreement), and (iii) all Common Stock issued
with respect to the Common Stock referred to in clause (i) or clause (ii) above
by way of stock dividend or stock split or in connection with any combination of
shares, merger, consolidation, recapitalization or other reorganization. All
shares of Executive Stock will continue to be Executive Stock in the hands of
any transferee, other than (x) the Company, (y) the Investors and (z) purchasers
pursuant to an offering registered with the Securities and Exchange Commission
pursuant to the Securities Act or purchasers pursuant to a public sale through a
market-maker, broker or dealer under Rule 144 (or any successor rule)
promulgated under the Securities Act.

                  "Exempt Transfers" shall have the meaning given to it in ss.2
(a) hereof.

                  "Family Group" means the Executive's spouse and descendants
(whether natural or adopted) and any trust formed and maintained solely for the
benefit of the Executive and/or the Executive's spouse and/or descendants.

                  "Investors" means Trivest Fund I, Ltd. and Trivest Equity
Partners I, Ltd.

                  "Person" means an individual, a partnership, a corporation, a
limited liability company, an association, a joint stock company, a trust, a
joint venture, an unincorporated organization and a governmental entity or any
department, agency or political subdivision thereof.

                  "Securities Act" means the Securities Act of 1933, as amended.

                  "Stock Option Plan" shall have the meaning given to it in the
Preliminary Statements to this Agreement.

                  "Stock Option Substitution Agreement" shall have the meaning
given to it in the Preliminary Statements to this Agreement.

                  "Subsidiary" means any corporation with respect to which a
specified Person (or a Subsidiary thereof) owns, directly or indirectly, a
majority of the common stock or has the power to vote or direct the voting of
sufficient securities to elect a majority of the directors.

                  (b) Interpretation. The words "herein," "hereof," "hereunder"
and other words of similar import refer to this Agreement as a whole, as the
same from time to time may be amended or supplemented and not

                                       72
<PAGE>   3
any particular section, paragraph, subparagraph or clause contained in this
Agreement. Wherever from the context it appears appropriate, each term stated in
either the singular or plural shall include the singular and the plural, and
pronouns stated in masculine, feminine or neuter gender shall include the
masculine, feminine and the neuter.

         2.       Restrictions on Transfer.

                  (a) Transfer of Executive Stock. The Executive will not sell,
pledge or otherwise directly or indirectly transfer (whether with or without
consideration and whether voluntarily or involuntarily or by operation of law)
any interest in or any beneficial interest in any shares of Executive Stock
except pursuant to the provisions of Section 4 hereof ("Exempt Transfers") and
except pursuant to the provisions of this Section 2. At least 60 days prior to
making any transfer other than an Exempt Transfer, the Executive will deliver a
written notice (the "Sale Notice") to the Company and the Investors. The Sale
Notice will disclose in reasonable detail the identity of the prospective
transferee(s) and the terms and conditions of the proposed transfer.

                  (b) First Refusal Rights. The Company may elect to purchase
all (but not less than all) of the shares of Executive Stock to be transferred
upon the same terms and conditions as those set forth in the Sale Notice by
delivering a written notice of such election to the Executive within 30 days
after the receipt of the Sale Notice by the Company. The Company shall
thereafter have up to 60 days to consummate the purchase and sale of Executive
Stock (the "Authorization Period"). If the Company does not elect to purchase
all of the shares of Executive Stock specified in the Sale Notice, the
Executive may transfer the shares of Executive Stock specified in the Sale
Notice at a price and on terms no more favorable to the transferee(s) thereof
than specified in the Sale Notice during the 60-day period immediately
following the Authorization Period. Any shares of Executive Stock not
transferred within such 60-day period will be subject to the provisions of this
Section 2(b) upon subsequent transfer.

                  (c) Certain Permitted Transfers. The restrictions contained in
this Section 2 will not apply with respect to transfers of Executive Stock (i)
pursuant to applicable laws of descent and distribution or (ii) among the
Executive's Family Group; provided that the restrictions contained in this
Section 2 will continue to be applicable to Executive Stock after any such
transfer; and provided further that the transferees of such Executive Stock
have agreed in writing to be bound by the provisions of this Agreement relating
to Executive Stock.

                  (d) Termination of Restrictions. The restrictions on the

transfer of Executive Stock set forth in this Section 2 will continue with
respect to each share of Executive Stock until the date on which such
Executive Stock has been transferred in a transaction permitted by this Section
2 (except in a transaction contemplated by Section 2(c)); provided, however,
that in any event the restrictions on transfers set forth in this Section 2
will terminate upon a Company Sale.

         3.       Additional Restrictions on Transfer.

                  (a) The certificates representing Executive Stock will bear
the following legend:

                  THE SECURITIES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO
                  RESTRICTIONS ON TRANSFER, CERTAIN REPURCHASE OPTIONS AND
                  CERTAIN OTHER AGREEMENTS SET FORTH IN A SHAREHOLDERS'
                  AGREEMENT AMONG THE COMPANY AND CERTAIN OF ITS SHAREHOLDERS,
                  DATED AS OF OCTOBER 20, 1997, A COPY OF WHICH MAY BE OBTAINED
                  BY THE HOLDER HEREOF AT THE COMPANY'S PRINCIPAL PLACE OF
                  BUSINESS WITHOUT CHARGE.

                  (b) Opinion of Counsel. No holder of Executive Stock may sell,
pledge or otherwise directly or indirectly transfer (whether with or without
consideration and whether voluntarily or involuntarily or by operation of law)
any Executive Stock (except pursuant to an effective registration statement
under the Securities Act) without first delivering to the Company an opinion of
counsel (reasonably acceptable in form and substance to the Company) that
neither registration nor qualification under the Securities Act and applicable
state securities laws is required in connection therewith.

                                       73
<PAGE>   4
                  (c) Lock-Up. Each holder of Executive Stock agrees not to
effect any public sale or other distribution of any Executive Stock or other
equity securities of the Company, or any securities convertible into or
exchangeable or exercisable for any of the Company's equity securities, during
the seven days prior to and the 120 days after the effectiveness of any
underwritten public offering, except as part of such underwritten public
offering or if otherwise permitted by the Company.

         4. Take-Along/Tag-Along.

                  (a) Take-Along. If the Investors propose to sell or convey, in
a single transaction or a series of transactions, any of the shares of Common
Stock owned by them, or any interest therein, to an independent third party
(including, without limitation, a sale of the Company by merger, consolidation,
sale of all or substantially all of its assets, sale of all of the outstanding
Common Stock or otherwise) (the"Approved Sale"), the Investors shall give prompt
written notice (the "Sale Notice") to the holders of Executive Stock setting
forth the terms and conditions of the proposed transfer, including the identity
of the independent third party, the number of shares of Common Stock to be
transferred, the per share price to be paid for the shares of Common Stock to be
transferred and the type and nature of the consideration to be received
therefor. By so indicating in the Sale Notice, the Investors shall be entitled
to require the holders of Executive Stock to sell to the independent third party
in the same transaction all of their shares of Common Stock and rights to
acquire shares of Common Stock (or, if the Investors are selling less than all
of their Common Stock, a percentage of each such holder's shares of Common Stock
and rights to acquire shares of Common Stock equivalent to the percentage of
Common Stock and rights to acquire shares of Common Stock to be sold by the
Investor), on the same terms and conditions set forth in the Sale Notice.
Without limitation as to the foregoing, the holders of Executive Stock will
consent to and raise no objections against the Approved Sale. If the Approved
Sale is structured as a merger or consolidation, each holder of Executive Stock
shall waive any dissenters' rights, appraisal rights or similar rights in
connection with such merger or consolidation. The holders of Executive Stock
will take all necessary and desirable actions in connection with the
consummation of any Approved Sale. For purposes of this ss.4, an "independent
third party" is any person who, on the date hereof, does not own in excess of 5%
of the Company's Common Stock on a fully-diluted basis, who is not controlling,
controlled by or under common control with any such 5% owner of the Company's
Common Stock and who is not the spouse, ancestor or descendant (by birth or
adoption) of any such 5% owner of the Company's Common Stock.

                  (b) Tag-Along. If the Investors shall issue a Sale Notice with
respect to an Approved Sale, the holders of Executive Stock, by written notice
to the Investors delivered within 10 days after the date of such Sale Notice,
shall be entitled to require that the Investors include in the proposed sale to
the independent third party in the same transaction all of their shares of
Common Stock and rights to acquire shares of Common Stock (or, if the Investors
are selling less than all of their Common Stock, a percentage of each such
holder's shares of Common Stock and rights to acquire shares of Common Stock
equivalent to the percentage of Common Stock and rights to acquire shares of
Common Stock to be sold by the Investors), on the same terms and conditions set
forth in the Sale Notice.

                  (c) Expenses of Sale. The Executive and the other holders of
Executive Stock (if any) will bear their pro rata share (based upon the number
of shares sold) of the costs of any sale of Executive Stock pursuant to an
Approved Sale to the extent that such costs are incurred for the benefit of all
holders of Common Stock and are not otherwise paid by the Company or the
acquiring party. Costs incurred by the Executive and the other holders of
Executive Stock (if any) on their own behalf will not be considered costs of the
transaction hereunder.

                  (d) Termination The provisions of this ss.4 will terminate
upon the completion of a Qualified Public Offering.

         5. Notices. Any notice provided for in this Agreement must be in
writing and must be either personally delivered, or mailed by certified or
registered mail, return receipt requested, postage prepaid to the recipient at
the address below indicated:

                  To the Company:

                  c/o Trivest II, Inc.

                                       74
<PAGE>   5
                  2665 South Bayshore Drive
                  Suite 800
                  Miami, Florida  33133
                  Attention: General Counsel

                  To the Executive or any holder(s) of Executive Stock:

                  at the address set forth on the signature page hereto

                  To the Investors:

                  c/o Trivest II, Inc.
                  2665 South Bayshore Drive
                  Suite 800
                  Miami, Florida  33133
                  Attention: General Counsel

or such other address or to the attention of such other person as the recipient
party shall have specified by prior written notice to the sending party. Any
notice under this Agreement will be deemed to have been given when so delivered
or mailed.

         6. Severability. Whenever possible, each provision of this Agreement
will be interpreted in such manner as to be effective and valid under applicable
law, but if any provision of this Agreement is held to be invalid, illegal or
unenforceable in any respect under any applicable law or rule in any
jurisdiction, such invalidity, illegality or unenforceability will not affect
any other provision or any other jurisdiction, but this Agreement will be
reformed, construed and enforced in such jurisdiction as if such invalid,
illegal or unenforceable provision had never been contained herein.

         7. Complete Agreement. This Agreement, those documents expressly
referred to herein and other documents of even date herewith embody the complete
agreement and understanding among the parties and supersede and preempt any
prior understandings, agreements or representations by or among the parties,
written or oral, which may have related to the subject matter hereof in any way.

         8. Counterparts. This Agreement may be executed on separate
counterparts, each of which is deemed to be an original and all of which taken
together constitute one and the same agreement. Any telecopied signature shall
be deemed a manually executed and delivered original.

         9. Successors and Assigns. This Agreement is intended to bind and inure
to the benefit of and be enforceable by the Executive, the Company and the
Investors, and their respective successors and assigns (including subsequent
holders of Executive Stock) and, where applicable, heirs and personal
representatives.

         10. Choice of Law. This Agreement shall be governed and construed in
accordance with the laws of the State of Florida without regard to conflicts of
laws principles thereof and all questions concerning the validity and
construction hereof shall be determined in accordance with the laws of said
state. Each party hereby irrevocably submits to the exclusive jurisdiction of
any state or federal court sitting in the County of Dade, State of Florida in
any action or proceeding arising out of or relating to this Agreement and hereby
irrevocably agrees, on behalf of itself or himself and on behalf of such party's
successor's and assigns, that all claims in respect of such action or proceeding
may be heard and determined in any such court and irrevocably waives any
objection such person may now or hereafter have as to the venue of any such
suit, action or proceeding brought in such a court or that such court is an
inconvenient forum. In the event that an action or proceeding arising out of or
relating to this Agreement shall be commenced in a court described in the second
sentence of this ss.10 and such court, by a final and nonappealable order, shall
refuse to exercise in personam jurisdiction over the Company, the Executive or
any Investor, as the case may be, then the parties hereto shall not be precluded
from litigating such action or proceeding in any other court of competent
jurisdiction.




                                       75

<PAGE>   6

         11. Waiver of Jury Trial. THE PARTIES HERETO HEREBY WAIVE TRIAL BY JURY
IN ANY JUDICIAL PROCEEDING INVOLVING, DIRECTLY OR INDIRECTLY, ANY MATTER
(WHETHER IN TORT, CONTRACT OR OTHERWISE) IN ANY WAY ARISING OUT OF, RELATED TO,
OR CONNECTED WITH THIS AGREEMENT, THE RELATED DOCUMENTS OR THE RELATIONSHIP
ESTABLISHED HEREUNDER.

         12. Remedies. Each of the parties to this Agreement will be entitled to
enforce its rights under this Agreement specifically, to recover damages by
reason of any breach of any provision of this Agreement and to exercise all
other rights existing in its favor. The parties hereto agree and acknowledge
that money damages may not be an adequate remedy for any breach of the
provisions of this Agreement and that any party may in its sole discretion apply
to any court of law or equity of competent jurisdiction for specific performance
and/or injunctive relief in order to enforce or prevent any violations of the
provisions of this Agreement.

         13. Amendments and Waivers. No provision of this Agreement may be
amended or waived without the prior written consent of the Company, the
Investors and the Executive.

         14. Business Days. Whenever the terms of this Agreement call for the
performance of a specific act on a specified date, which date falls on a
Saturday, Sunday or legal holiday, the date for the performance of such act
shall be postponed to the next succeeding regular business day following such
Saturday, Sunday or legal holiday.

         15. Failure to Deliver Stock. If the Executive (or the Executive's
estate or any other representative of the Executive or holder of Executive
Stock) who has become obligated to sell shares of Executive Stock to the Company
hereunder shall fail to deliver such shares on the terms and in accordance with
this Agreement, the Company, in addition to all other remedies it may have, may
send to the such obligated party by registered mail, return receipt requested,
the purchase price for such shares on the terms provided for in this Agreement.
Thereupon, the Company, upon written notice to such holder, shall cancel on its
books the certificates representing the Executive Stock to be sold; and
thereupon, all of such obligated holder's rights in and to such Executive Stock
shall terminate.

         16. No Third Party Beneficiary. Except for the parties to this
Agreement and their respective successors and assigns, nothing expressed or
implied in this Agreement is intended, or will be construed, to confer upon or
give any person other than the parties hereto and their respective successors
and assigns any rights or remedies under or by reason of this Agreement.

         IN WITNESS WHEREOF, the parties have executed this Agreement on the day
and year first above written.


                                      PENDA CORPORATION




                                      By:
                                          --------------------------------
                                               Jack L. Thompson, President
                                               and Chief Executive Officer


                                      ------------------------------------
                                      XXXXX

                                      Address:

                                      c/o Penda Corporation
                                      2344 W. Wisconsin Street
                                      P.O. Box 449


                                       76


<PAGE>   7
                                      Portage, Wisconsin  53901-0449



                                      TRIVEST FUND I, LTD.

                                      By:  Trivest Fund Managers, Ltd.,
                                           General Partner

                                           Trivest Group, Inc., General Partner

                                           By:
                                               --------------------------------
                                                   Peter C. Brockway
                                                   Executive Vice President


                                      TRIVEST EQUITY PARTNERS I, LTD.

                                      By: Trivest Fund Managers, Ltd., General
                                          Partner

                                          Trivest Group, Inc., General Partner

                                          By:
                                              --------------------------------
                                                  Peter C. Brockway
                                                  Executive Vice President




                                       77