<PAGE>

                                                                   Exhibit 10.31


                       Preferred Employers Holdings, Inc.
                            10800 Biscayne Boulevard
                              Miami, Florida 33161


                                             Dated as of January 1, 1999

Mr. D. Mark Olson
455 Holiday Drive
Hallandale, FL 33009

Dear Mark:

          This letter sets forth the terms of our agreement (the "AGREEMENT")
with respect to your employment with Preferred Employers Holdings, Inc. (the
"COMPANY").

          1. EMPLOYMENT. Subject to Sections 5, 6 and 7 hereof, the Company
hereby agrees to employ you, and you hereby accept such employment, for a one
year period beginning as of January 1, 1999 and ending December 31, 1999 (such
period, as may be extended as hereinafter provided, called the "TERM"), upon the
terms and conditions set forth herein. This Agreement shall be automatically
renewed for successive one-year periods, unless either you or the Company
notifies the other within 90 days of the expiration of the initial term or any
renewal period, as the case maybe, of your or its intention not to renew this
Agreement.

          2. POSITION AND DUTIES. During your employment hereunder, you shall
serve as Executive Vice President of the Company (and President and Chief
Executive Officer of Preferred Employers Group, Inc.) and shall have such duties
consistent with such offices as from time to time may be prescribed by the Board
of Directors of the Company (the "BOARD") or the Chairman and Chief Executive
Officer of the Company. You shall report to the Board and the Chairman and Chief
Executive Officer of the Company on an overall basis, and the President and
Chief Operating Officer on a day-to-day basis. You shall perform and discharge
such duties on a full-time basis, and shall devote your best talents, efforts
and abilities to the performance of your duties hereunder. Your primary place of
employment shall be the executive offices of the Company in the greater Miami,
Florida area (including Dade and Broward Counties), subject to such reasonable
travel as the performance of your duties in the business of the Company may
require.

          3. BASE SALARY; EXPENSES. (a) During your employment hereunder, the
Company shall pay to you a base salary at the annual rate of $250,000 (the "BASE
SALARY"), payable in accordance with the customary payroll practices of the
Company.

                  (b) The Company shall reimburse you, in accordance with
generally applicable policies of the Company, for all reasonable business
related expenses incurred by you in the performance of your duties, including
but not limited to, travel and lodging, customer meals and entertainment,
telephone and fax charges.

                  (c) You may be entitled to receive a bonus under the Company's
Executive Bonus Compensation Plan, subject to the terms and conditions thereof.

<PAGE>

Mr. D. Mark Olson
Dated as of January 1, 1999
Page 2


                  (d) During the Term, the Company shall pay you an aggregate
amount of $12,000 per year in an automobile allowance to cover automobile
expenses, such as automobile lease or loan payments, registration, insurance,
repairs, maintenance, license fees, parking, gasoline and oil incurred by you
incident to your use of an automobile in connection with your duties hereunder.

          4. BENEFITS. The Company shall make available to you any and all
employee fringe benefits, in accordance with their terms and conditions, which
the Company may make available generally to its other executive officers (e.g.,
any medical, vacation, holidays, dental and 401(k) plans).

          5. TERMINATION OF EMPLOYMENT FOR CAUSE; RESIGNATION; DEATH;
DISABILITY. Upon (a) the Company's termination of your employment for Cause,
your resignation from employment with the Company (other than for Good Reason
within 6 months following a Change of Control), or the termination of your
employment due to your death or Disability, the Company shall have no further
liability or obligation to you hereunder or otherwise in respect of your
employment, other than its obligation to pay to you (i) the Base Salary that is
accrued but unpaid as of the date your employment with the Company terminates
and (ii) any unpaid expense reimbursements or unpaid vested benefit payments
accrued prior to the date of termination.

          6. TERMINATION OF EMPLOYMENT WITHOUT CAUSE. Upon the Company's
termination of your employment without Cause, the Company shall pay to you (i)
your Base Salary, at the rate in effect at the date of termination, for the then
remaining duration of the Term or 90 days after the date your employment with
the Company terminates, whichever is greater, in cash, in one lump sum, within
thirty (30) days from the date of termination plus (ii) within five business
days following the date of determination, the amount of bonus to which you would
have been entitled to under the Company's Executive Bonus Compensation Plan as
if you were still employed by the Company as of such date, based upon your
percentage of the Executive Bonus Compensation Plan in effect on the date of
termination, which amount shall be pro-rated based upon the number of days in
which you were employed in the year of termination.

          7. TERMINATION AFTER A CHANGE OF CONTROL. In the event your employment
with the Company is terminated by the Company without Cause or by you for Good
Reason within six months following a Change of Control, the Company shall pay to
you (i) your Base Salary, at the rate in effect at the date of termination, for
the then remaining duration of the Term or 90 days after the date your
employment with the Company terminates, whichever is greater, in cash, in one
lump sum, within thirty (30) days from the date of termination plus (ii) within
five business days following the date of determination, the amount of bonus to
which you would have been entitled to under the Company's Executive Bonus
Compensation Plan as if you were still employed by the Company as of such date,
based upon your percentage of the Executive Bonus Compensation Plan in effect on
the date of termination, which amount shall be pro-rated based upon the number
of days in which you were employed in the year of termination. Notwithstanding
the foregoing, all options granted to you by the Company shall automatically
vest upon a Change of Control, whether or not you are terminated.

          8. For purposes of this Agreement, the following capitalized terms
shall have the meanings indicated below:

<PAGE>

Mr. D. Mark Olson
Dated as of January 1, 1999
Page 3


     "CHANGE OF CONTROL" shall mean:

            (a) The acquisition (other than by the Company) by any person,
entity or "group", within the meaning of Section 13(d) or 14(d)(2) of the
Securities Exchange Act of 1934 (the "EXCHANGE ACT"), other than any employee
benefit plan of the Company or its affiliates, of beneficial ownership (within
the meaning of Rule 13d-3 promulgated under the Exchange Act) of 30% or more of
either (i) the then outstanding shares of common stock or (ii) the combined
voting power of the Company's then outstanding voting securities entitled to
vote generally in the election of directors;

            (b) Individuals who, as of the close of business on the date of
execution of this Agreement, constitute the Board (the "INCUMBENT BOARD") cease
for any reason to constitute at least a majority of the Board; provided that any
person becoming a director subsequent to the date hereof whose election, or
nomination for election by the Company's stockholders, was approved by a vote of
at least a majority of the members of the Incumbent Board then comprising the
Board (other than an election or nomination of an individual whose initial
assumption of office is in connection with an actual or threatened election
contest relating to the election of directors of the Company, within the meaning
of Rule 14a-11 of Regulation 14A promulgated under the Exchange Act) shall be
for purposes of this Agreement, considered as though such person were a member
of the Incumbent Board, or

            (c) Approval by the stockholders of the Company of (i) a
reorganization, merger, or consolidation, in each case, with respect to which
persons who were the stockholders of the Company immediately prior to such
reorganization, merger or consolidation do not, immediately thereafter, own more
than 50% of the combined voting power entitled to vote generally in the election
of directors of the reorganized, merged or consolidated company's then
outstanding voting securities, or (ii) a liquidation or dissolution of the
Company, or (iii) the sale of all or substantially all of the assets of the
Company.

      "CAUSE" shall mean: (1) a felony conviction of you (or a plea by you of
NOLO CONTENDERE to a felony charge); (2) the breach by you of any material
provision of this Agreement, which breach, if curable, is not remedied within
thirty (30) days after your receipt of written notice thereof provided, however,
that the Company need not be obligated to permit you to cure any breach which
has been the subject of a prior written notice; (3) an act of gross misconduct
in connection with your duties hereunder; or (4) habitual or material neglect of
your duties to the Company (as determined in good faith by the Board) which is
not remedied within 30 days after your receipt of written notice thereof).

      "GOOD REASON" shall mean following a Change of Control, (i) the material
failure of the Company to comply with the provisions of this Agreement which
failure is not remedied within ten (10) days after the Company's receipt of
written notice specifying in reasonable detail the factors constituting such
failure; (ii) any purported termination by the Company of your employment other
than in accordance with this Agreement; or (iii) the assignment to you of duties
and responsibilities inconsistent with those duties and responsibilities
customarily assigned to individuals holding the position of Executive Vice
President of a company of comparable size to the Company or the substantial
diminution by the Company of your duties and responsibilities.

<PAGE>

Mr. D. Mark Olson
Dated as of January 1, 1999
Page 4


      "DISABILITY" shall mean any physical or mental condition which renders you
unable to perform the services required of you pursuant to this Agreement for a
period of six (6) successive months, or an aggregate of six (6) months in any
twelve (12) month period.

          9. TRADE SECRETS; CONFIDENTIALITY; RESTRICTIVE COVENANTS.

                  (a) TRADE SECRETS; CONFIDENTIALITY. You acknowledge that you
will have access to valuable trade secrets and confidential, non-public
information of the Company including, without limitation, product and sales
information, technologies, strategies, customer lists, business methods and
processes, marketing, promotional, pricing, financial information and data
relating to employees and consultants (individually and collectively,
"CONFIDENTIAL INFORMATION"). Confidential Information shall not include
information in your possession prior to the date of your initial employment with
the Company, or information required to be disclosed pursuant to applicable
laws. You agree that during your employment with the Company and at all times
thereafter, you will not use or disclose any Confidential Information or
otherwise make any Confidential Information available to any person except as
otherwise directed in writing by the Company.

                  (b) RESTRICTIVE COVENANTS. You agree that during your
employment with the Company and for the one-year period commencing on the date
your employment with the Company terminates, you will not directly or
indirectly, (i) own, manage, operate, join, advise, control or otherwise
participate in or be connected as an officer, employee, partner, investor,
creditor, guarantor, advisor or consultant in any business which may compete
against or is in any material way related to the Company's (or any of its
subsidiaries and affiliates) business within any area where the Company conducts
business operations; provided that you may own securities in any publicly held
corporation but only to the extent you do not own of record or beneficially more
than 5% of the outstanding beneficial ownership of all classes of securities of
such corporation, (ii) either for your own account or for any individual,
corporation, partnership, joint venture, firm, company, association or other
entity, including a government or political subdivision or any agency or
instrumentality thereof, solicit, interfere with or hire, any employee of the
Company (or any of its subsidiaries and affiliates) or endeavor to cause any
such employee to leave his or her employment with, or induce or attempt to
induce any such employee to terminate or breach his or her employment with or
otherwise change the terms of his or her employment with the Company (or any of
its subsidiaries and affiliates), and (iii) solicit, induce or attempt to induce
any past, current or future customer of the Company (or any of its subsidiaries
and affiliates), wherever such customer may be located, to cease doing business,
in whole or in part, or otherwise alter its business relationship with the
Company (or any of its subsidiaries or affiliates).

                  (c) The Company shall be entitled to an injunction restraining
you from the breach of any provisions of this paragraph 9. Nothing contained
herein shall be construed to prohibit the Company from pursuing any other
remedies for any breach or a threatened breach of this Agreement. The provisions
of this Section 9 shall survive the termination of this Agreement.

          10. MISCELLANEOUS. If any provision of this Agreement, or portion
thereof, shall be held invalid or unenforceable by a court of competent
jurisdiction, such invalidity or unenforceability shall attach only to such
provision or portion thereof, and this Agreement shall be carried out as if any
such invalid or unenforceable provision or portion thereof were not contained
herein. In addition, any such invalid or unenforceable provision or portion
thereof shall be deemed, 

<PAGE>

Mr. D. Mark Olson
Dated as of January 1, 1999
Page 5


without further action on the part of the parties hereto, modified, amended or
limited to the extent necessary to render the same valid and enforceable; such
modification, amendment or limitation to apply in the particular jurisdiction
where such adjudication is made.

          11. WITHHOLDING. All payments required to be made to you by the
Company hereunder shall be subject to withholding taxes, social security and
other payroll deductions in accordance with applicable law and the Company's
policies.

          12. ENTIRE AGREEMENT; TERMINATION. The employment agreement, dated as
of July 7, 1997, between the Company and you is hereby terminated, is null and
void and of no further force and effect. This Agreement sets forth the entire
agreement of the parties hereto in respect of the subject matter contained
herein and supersedes all prior agreements, promises, covenants, arrangements,
communications, representations or warranties, whether oral or written, of any
party hereto, including without limitation that certain employment agreement,
dated as of July 7, 1997, between you and the Company. Notwithstanding the
foregoing, the Company and you acknowledge and agree that those certain stock
option agreements, dated July 7, 1997, between you and the Company, pursuant to
the Company's 1996 Stock Option Plan, and pursuant to the Share Escrow
Agreement, dated February 5, 1997, by and among the Company, Howard Odzer and
the escrow agent, and those certain bonus stock option agreements, dated July 7,
1997, between you and the Company, pursuant to the Company's 1996 Stock Option
Plan, and pursuant to the Share Escrow Agreement, dated February 5, 1997, by and
among the Company, Howard Odzer and the escrow agent, shall remain in full force
and effect.

          13. COUNTERPARTS. This Agreement may be signed in any number of
counterparts, each of which shall be an original, with the same effect as if the
signatures thereto and hereto were upon the same instrument.

          14. WAIVER. The waiver by the Company of a breach of any provision of
this Agreement by you shall not operate or be construed as a waiver of any
subsequent or other breach by you. Any such waiver must be in writing.

          15. GOVERNING LAW. This agreement shall be construed in accordance
with and governed by the laws of the State of Florida, without regard to the
conflicts of laws rules thereof.

<PAGE>

Mr. D. Mark Olson
Dated as of January 1, 1999
Page 6


          If the foregoing correctly sets forth your understanding of our
agreement, please so indicate by signing and returning to us a copy of this
Agreement.

                                             Very truly yours,

                                             PREFERRED EMPLOYERS HOLDINGS, INC.



                                             By: /s/ William R. Dresback
                                                --------------------------------
                                                William R. Dresback
                                                Senior Vice President and Chief
                                                Financial Officer

Accepted and agreed to on
the 1st day of January, 1999

/s/ D. Mark Olson
-----------------------------------
D. Mark Olson


<PAGE>

                       Preferred Employers Holdings, Inc.
                            10800 Biscayne Boulevard
                                 Miami, FL 33161


                                             February 26, 1999

Mr. D. Mark Olson
455 Holiday Drive
Hallandale, FL 33009

Dear Mark:

         Reference is hereby made to that certain Employment Agreement (the
"Agreement") dated as of January 1, 1999 between you and Preferred Employers
Holdings, Inc. (the "Company"). Notwithstanding the provisions of Section 9(b)
of the Agreement, the Company and you hereby agree that in the event your
employment is terminated with the Company without Cause or for Good Reason
within six months following a Change of Control then the restriction not to
compete as set forth in Section 9(b)(i) of the Agreement shall be limited to
activities which are in direct competition with the business activities then
conducted by the Company.

         Except as modified herein, all of the terms, provisions and conditions
of the Agreement shall remain in full force and effect and the rights and
obligations of the parties shall be unaffected by this letter and shall continue
as provided in the Agreement. If this letter accurately sets forth the matters
contained herein, please so indicate by executing this letter in the space
provided for your signature and returning the counterpart to us, whereupon this
letter shall become a binding agreement between us in accordance with its terms.


                                             Very truly yours,

                                             PREFERRED EMPLOYERS HOLDINGS, INC.



                                             By: /s/ William R. Dresback
                                                --------------------------------
                                                Name:  William R. Dresback
                                                Title: CFO

Accepted and Agreed
March 5, 1999

/s/ D. Mark Olson
---------------------------
D. Mark Olson