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                                                                  EXHIBIT 10.18

                              EMPLOYMENT AGREEMENT

         THIS AMENDED AND RESTATED EMPLOYMENT AGREEMENT ("Agreement") between
ZENITH NATIONAL INSURANCE CORP., a Delaware corporation (hereinafter referred to
as "Zenith"), and STANLEY R. ZAX (hereinafter referred to as "Employee") is
hereby amended and restated in its entirety effective December 11, 1997 (the
"Effective Date").

                                    RECITALS

         WHEREAS, Employee is presently employed as Chairman of the Board and
President of Zenith Insurance Company, a subsidiary of Zenith, pursuant to a
written Employment Agreement originally dated as of December 9, 1981, which
agreement has been extended and modified from time to time, and is also employed
as Chairman of the Board and President of Zenith and certain of its other
subsidiaries (Zenith and all of its subsidiaries collectively referred to
hereinafter as "Employer"); and

         WHEREAS, Zenith and Employee deem it in their respective best interests
to extend the term of said Employment Agreement at the present time and modify
certain other provisions thereof;

         NOW, THEREFORE, it is agreed as follows:

1.       AMENDED AND RESTATED EMPLOYMENT AGREEMENT. The Agreement is hereby
amended and restated in its entirety and the term thereof is hereby extended as
hereinafter provided.

2.       ENGAGEMENT AND DUTIES. During the Term of Employment as defined in
Paragraph 3 of this Agreement:

                  2.1 Employer hereby employs Employee and Employee does hereby
agree to be employed by Employer as Chairman of the Board, President, and Chief
Executive Officer of Zenith and in such other capacities at Zenith and at each
of the corporations which comprise Employer as shall hereafter be agreed upon by
Employee, the Board of Directors of Zenith and the boards of directors of such
other corporations.

                  2.2 Employee shall perform the normal duties of such offices
and such other executive duties as may from time to time be assigned to him by
and in accordance with instructions and directions of the Board of Directors of
Zenith. Both Employee and Employer hereby expressly recognize that the services
described herein shall be performed to the reasonable satisfaction of the Board
of Directors of Zenith.

                  2.3 Employee shall perform the duties contemplated hereunder
at his principal office located in Los Angeles County, California; provided,
however, Employee shall travel outside Los Angeles County to the extent he
reasonably deems it necessary or appropriate in the performance of his duties
hereunder.

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                  2.4 Employee, during the Term of Employment, shall devote his
time, attention, energies, skill and best efforts to the performance of his
duties for and on behalf of Employer.

3.       TERM OF EMPLOYMENT. The term of employment hereunder shall be a period
commencing on the Effective Date and terminating December 31, 2006 ("Expiration
Date"), unless sooner terminated as elsewhere provided herein ("Term of
Employment").

4.       COMPENSATION. As full and complete consideration for the performance of
his duties and the rendition of any and all services under this Agreement,
Employee shall be compensated as follows:

                  4.1 Employee shall be paid the following amounts, subject to
such other increases as the Board of Directors of Zenith may from time to time
determine ("Base Compensation"):

                           (a)      From the Effective Date through December 31,
2000: $1,000,000 per year;

                           (b)      From January 1, 2001 through December 31,
2002: $1,200,000 per year;

                           (c)      From January 1, 2003 through December 31,
2004: $1,350,000 per year; and

                           (d)      From January 1, 2005 through December 31,
2006: $1,500,000 per year.

                  4.2 In addition to the Base Compensation, Employee shall be a
participant in the Executive Officer Bonus Plan of Zenith.

                  4.3 All compensation hereunder shall be paid by Employer, as
allocated from time to time among the different corporations which comprise
Employer by the Audit Committee of Zenith, and shall comply with all relevant
governmental directives, rules and regulations which may be in effect from time
to time. All Base Compensation shall be payable ratably twice each month, or
more or less often in accordance with the normal payroll practices of Employer.

5.       BUSINESS EXPENSES. Employee shall be reimbursed for reasonable and
necessary expenses duly incurred in connection with the duties to be performed
and the services to be rendered by Employee to Employer under and pursuant to
this Agreement, upon submission of itemized expense statements in the manner and
at times specified by Employer for officers of Employer. In addition, Employee
shall be entitled to the exclusive full time use of one deluxe automobile of his
choice, to be replaced from time to time at Employee's discretion.

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6.   EMPLOYEE BENEFITS.

                  6.1 Employee shall be entitled to participate in all employee
insurance, retirement and other benefit plans for which he qualifies and which
may be in effect from time to time. Notwithstanding the foregoing, nothing
contained in this Agreement shall prohibit or limit the right of Employer to
discontinue, modify, or amend any plan or benefit in its absolute discretion at
any time, provided, however, that any such discontinuance, modification or
amendment shall apply to employees of Employer generally, or to a defined group
of such employees, and shall not apply solely to Employee.

                  6.2 Employee shall be entitled each year to a vacation in
accordance with standard employment practices, during which time his
compensation shall be paid in full. Each vacation shall be taken during a period
mutually satisfactory to both Employer and Employee.

                  6.3 During the Term of Employment, Zenith shall provide
Employee with life insurance coverage with an aggregate face amount equal to at
least $6,125,000 of which $5 million shall be term life insurance.

7.       DEATH DURING EMPLOYMENT. If Employee shall die during the Term of
Employment, Employer shall pay the compensation which could otherwise be payable
to Employee pursuant to Paragraphs 4.1 and 4.2 of this Agreement, up to the end
of the twelfth month following the month in which his death occurred (a) to
Employee's spouse, if living, (b) if his spouse is not then living, to his then
living issue by right of representation, and (c) if none of the above are then
living, to his estate.

8.       ACKNOWLEDGMENT OF PECULIAR VALUE OF SERVICES.

                  8.1 Employee acknowledges that the services which he has
agreed to render during the Term of Employment under this Agreement are special,
unique, unusual, extraordinary, and of an intellectual character, and therefore
are of peculiar value to Employer.

                  8.2 Employee further acknowledges that because of the
character of said services the remedy at law for any breach by him of this
Agreement may be enforced by an injunction in a suit in equity, without the
necessity of proving actual damage, and that a temporary injunction may be
granted immediately upon the commencement of any such suit, and without notice.
Nothing herein contained shall be construed as prohibiting Employer from
pursuing any other remedies available to Employer from such breach or threatened
breach, including the recovery of damages from Employee.

9.       DISCLOSURE OF INFORMATION.

                  9.1 Employee acknowledges that the list of Employer's
customers, as they may exist from time to time, and Employer's trade secrets and
other confidential information are valuable, special and unique assets of
Employer's business. Employee will not, during or after the Term of Employment,
disclose to any person, firm,

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corporation, association, or any other entity or use for his own benefit, any
list of Employer's customers, or any part thereof, or any of Employer's trade
secrets or other confidential information, for any reason or purpose whatsoever.

                  9.2 Employee agrees that upon leaving the employ of Employer
he will deliver to Employer and not keep or deliver to anyone else, any and all
memoranda, specifications, documents and in general any and all material
relating to Employer's business that he may have under his possession or
control.

                  9.3 Employee recognizes that he will possess confidential
information about other employees of Employer relating to their education,
experience, skills, abilities, compensation and benefits, and interpersonal
relationships with customers of Employer. The Employee recognizes that the
information he will possess about these other employees is not generally known,
is of substantial value to Employer in developing its products and in securing
and retaining customers, and will be acquired by him because of his business
position with Employer. Employee agrees that, during the period ending on the
last day of the one-year period following his termination of employment, he will
not, directly or indirectly, solicit or recruit any employee of Employer for the
purpose of being employed by him, or any business, individual, partner, firm,
corporation or other entity that is then in competition with Employer
("Competitor") on whose behalf he is acting as an agent, representative or
employee. The Employee further agrees that he will not convey any such
confidential information or trade secrets about other employees of Employer to
anyone affiliated with him or to any Competitor.

                  9.4 Employee further acknowledges that the remedy at law for
any breach by him of the covenants contained in Paragraphs 9.1 and 9.2 will be
inadequate and that in the event of a breach, or threatened breach, by Employee
of the covenants contained therein, Employer shall be entitled to an injunction
restraining Employee from using, for his own benefit, and/or from disclosing, in
whole or in part, the list of Employer's customers, and/or Employer's trade
secrets or other confidential information, and/or from rendering any services to
any person, firm, corporation, association or other entity to whom such a list,
and/or such trade secrets or other confidential information, in whole or in
part, have been disclosed, or are threatened to be disclosed and such other
declaratory relief as is proper to cause Employee to return to Employer any and
all memoranda, specifications, documents and all other material relating to
Employer's business that he may have under his possession or control. Nothing
herein shall be construed as prohibiting Employer from pursuing any other
remedies available to Employer from such breach or threatened breach, including
the recovery of damages from Employee. The provisions of this Paragraph 9 shall
survive the expiration or termination, for any reason, of this Agreement and of
Employee's employment.

10.      TERMINATION OF AGREEMENT BY EMPLOYER. Should any of the following
events occur, Employer may terminate this Agreement by giving written notice
thereof to Employee, which notice shall be effective immediately:

                  (a)      Employee is physically or mentally incapacitated for
a period of one hundred eighty (180) consecutive days. Employee shall be deemed
to be

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physically or mentally incapacitated if he is unable for any reason whatsoever
to devote his full time and efforts to the business of Employer.

                  (b)      Employee breaches any of his material obligations
under this Agreement.

                  10.1 Should Employer terminate the Term of Employment prior to
the Expiration Date pursuant to Paragraph 10(a) hereof, Employer shall thereupon
pay to Employee, in complete satisfaction of its obligations under this
Agreement, the compensation which would otherwise be payable to him pursuant to
Paragraphs 4.1 and 4.2 of this Agreement up to the end of the twelfth month
following the month in which such termination occurred (less any amounts payable
to Employee pursuant to any long-term disability plan in effect at the time of
such termination). Should Employer terminate the Term of Employment prior to the
Expiration Date pursuant to Paragraph 10(b) hereof, Employer shall pay to
Employee in complete satisfaction of its obligations under this Agreement and
without waiving any rights which it or its subsidiaries may have against
Employee, the compensation which would otherwise be payable to him pursuant to
Paragraph 4.1 of this Agreement up to the end of the month in which such
termination occurs and Employer shall not be obligated to make any payments to
Employee pursuant to Paragraph 4.2 of the Agreement.

                  10.2 Subject to the provisions of Paragraph 11.2 hereof,
should Employer terminate the Term of Employment prior to the Expiration Date
for any reason other than as set forth in Paragraphs 10(a) and 10(b) hereof,
Employer shall thereupon pay to Employee, in complete satisfaction of its
obligations under this Agreement, the compensation which would otherwise be
payable to him pursuant to Paragraphs 4.1 and 4.2 of this Agreement had Employee
continued to be employed through the Expiration Date, assuming, for purposes of
this Paragraph 10.2, that the annual bonus payable to Employee pursuant to
Paragraph 4.2 of this Agreement for each year of the remaining term is equal to
the highest annual bonus paid or payable to Employee during the three
consecutive years immediately preceding his termination of employment.

11.      CHANGE IN CONTROL; TERMINATION OF AGREEMENT BY EMPLOYEE OR EMPLOYER. In
the event of a Change in Control (as defined below) at any time during the Term
of Employment, all stock option rights, stock appreciation rights, and any and
all other similar rights theretofore granted to Employee, including, but not
limited to, the Stock Option Agreement entered into with Zenith, effective as of
March 15, 1996 (the "Option"), shall vest and shall then be exercisable in full.
In the event Employee ceases to be an employee of Zenith within 270 days
following a Change in Control of Zenith, in lieu of exercise of the Option,
Employee (or Employee's executors or administrators or the person or persons who
acquire Employee's rights to exercise the Option by bequest or inheritance) may,
in his or their sole discretion, elect, by giving notice of such election to
Zenith at its principal corporate headquarters within 90 days following
Employee's termination of employment, to receive cash equal in value to the
excess of the fair market value on the date of such election of the remaining
shares subject to the Option over the purchase price of such shares. Such
payment shall be made to Employee not less than five (5) nor more than fourteen
(14) days after Zenith's receipt of such notice.

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                  11.1 Employee may, within 180 days after the effective date of
any such Change in Control, deliver to Zenith a written notice of his election
to terminate the Term of Employment, effective as of a date set forth in said
notice, which effective date shall be not less than 30 days nor more than 90
days after the date of delivery of such written notice.

                  11.2 Notwithstanding anything in this Agreement to the
contrary, in the event of a Change in Control, should Employee terminate the
Term of Employment prior to the Expiration Date pursuant to Paragraph 11.1
hereof, or should Employer terminate the Term of Employment prior to the
Expiration Date for any reason other than as set forth in Paragraphs 10(a) and
10(b) hereof, then, effective as of the date set forth in Employee's or
Employer's notice to terminate the Term of Employment, Employee shall be
entitled to the benefits provided below (hereinafter referred to as "Severance
Payments"):

                           (i)      Zenith shall pay to Employee his Base
Compensation through the effective date of the notice to terminate the Term of
Employment, at the rate in effect at the time such notice of termination is
given, plus all other amounts to which he is entitled under any compensation
plan of Employer, in each case at the time such payments are due;

                           (ii)     Zenith shall pay to Employee a cash lump sum
payment, no later than the fifteenth day following the effective date of the
notice to terminate the Term of Employment, equal to the greater of (a) two
times the sum of (x) his Base Compensation at the rate in effect as of the
effective date of the notice to terminate the Term of Employment and (y) the
highest annual bonus paid or payable to Employee during the three consecutive
years immediately preceding his termination of employment, or (b) the "actuarial
equivalent" of all Base Compensation and bonus payments that would have been
payable to Employee pursuant to Paragraphs 4.1 and 4.2 of this Agreement had
Employee continued to be employed through the Expiration Date, assuming, for
purposes of this Paragraph, that the annual bonus payable to Employee pursuant
to Paragraph 4.2 of this Agreement for each year of such remaining term is equal
to the highest annual bonus paid or payable to Employee during the three
consecutive years immediately preceding his termination of employment. For
purposes of this subparagraph 11.2(ii), "actuarial equivalent" shall be
determined by an actuary selected by Zenith, subject to approval by Employee,
and calculated in accordance with the actuarial assumptions used by the Pension
Benefit Guaranty Corporation to value liabilities for pension plans terminating
as of the effective date of Employee's or Employer's notice to terminate the
Term of Employment;

                           (iii)    During the period beginning as of the
effective date of Employee's or Employer's notice to terminate the Term of
Employment until the Expiration Date, Zenith shall, at its cost, arrange to
provide Employee with life, disability, dental, accident and group health
insurance benefits substantially similar to those that he was receiving
immediately prior to the effective date of the notice to terminate the Term of
Employment plus an additional amount necessary to reimburse Employee for any
taxes imposed solely by reason of his receipt of such benefits

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following his termination of employment. Notwithstanding the foregoing, Zenith
shall not provide any benefit otherwise receivable by Employee pursuant to this
subparagraph 11.2(iii) if an equivalent benefit actually received by him at any
time during the period of coverage, and any such benefit actually received by
him shall be reported to Zenith.

                  11.3 For purposes of this Agreement, a Change in Control shall
mean either (i) a merger or consolidation of Zenith with or into another company
or corporation, other than (a) a merger or consolidation which would result in
the voting securities of Zenith outstanding immediately prior thereto continuing
to represent (either by remaining outstanding or by being converted into voting
securities of the surviving entity) at least 75% of the combined voting power of
the voting securities of Zenith or such surviving entity outstanding immediately
after such merger or consolidation or (b) a merger or consolidation effected to
implement a recapitalization of Zenith (or similar transaction) in which no
"person" (as such term is used in Sections 13(d) and 14(d) of the Securities
Exchange Act of 1934, as amended) acquires Zenith more than 50% of the combined
voting power of Zenith's then outstanding securities; or (ii) an assignment of
this Agreement by Zenith under the provisions of Paragraph 15.2 hereof; or (iii)
the sale of all or substantially all of Zenith's assets; or (iv) a change in the
identities of a majority of the members of the Board of Directors of Zenith
within a one-year period or less; or (v) any other transaction which would
require any party or affiliated group of parties to obtain approval from, or
require such transactions to be presented for approval by, the California
Insurance Commissioner (assuming there is no preemption of California insurance
laws by Federal Law).

                  11.4 Notwithstanding anything to the contrary in this
Agreement, in the event that Employee becomes entitled to the Severance
Payments, if any of the Severance Payments will be subject to the tax (the
"Excise Tax") imposed by section 4999 of the Internal Revenue Code of 1986, as
amended (the "Code"), Zenith shall pay to Employee an additional amount (the
"Gross-Up Payment") such that the net amount retained by Employee, after
deduction of any Excise Tax on the Total Payments (as hereinafter defined) and
any federal, state and local income and other tax and Excise Tax upon the
payment provided for by this Paragraph 11.4, shall be equal to the Total
Payments. For purposes of determining whether any of the Total Payments will be
subject to the Excise Tax and the amount of such Excise Tax, (i) any other
payments or benefits received or to be received by Employee in connection with a
Change in Control or Employee's termination of employment (whether pursuant to
the terms of this Agreement or any other plan, arrangement or agreement with
Employer, any person whose actions result in a change in control or any person
affiliated with Employer or such person (which, together with Severance
Payments, shall constitute "Total Payments"), shall be treated as "parachute
payments" within the meaning of section 280G(b)(2) of the Code, and all "excess
parachute payments" within the meaning of section 280G(b)(1) shall be treated as
subject to the Excise Tax, unless in the opinion of tax counsel selected by
Zenith's independent auditors and acceptable to Employee, such other payments or
benefits (in whole or in part) do not constitute parachute payments, or such
excess parachute payments (in whole or in part) represent reasonable
compensation for services actually rendered within the meaning of section
280G(b)(4) of the Code in excess of the base amount, within the meaning of
section 280G(b)(3) of the Code, or are otherwise not

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subject to the Excise Tax, (ii) the amount of the Total Payments which shall be
treated as subject to the Excise Tax shall be equal to the lesser of (A) the
total amount of the Total Payments or (B) the amount of excess parachute
payments within the meaning of section 280G(b)(1) (after applying clause (i),
above), and (iii) the value of any non-cash benefits or any deferred payment or
benefit shall be determined by Zenith's independent auditors in accordance with
the principles of sections 280G(d)(3) and (4) of the Code. For purposes of
determining the amount of the Gross-Up Payment, Employee shall be deemed to pay
federal income taxes at the highest marginal rate of federal income taxation in
the calendar year in which the Gross-Up Payment is to be made and state and
local income taxes at the highest marginal rate of taxation in the state and
locality of Employee's residence on the date of termination of employment, net
of the maximum reduction in federal income taxes which could be obtained from
deduction of such state and local taxes. In the event that the Excise Tax is
subsequently determined to be less than the amount taken into account hereunder
at the time of termination of Employee's employment, Employee shall repay to
Zenith, at the time that the amount of such reduction in Excise Tax is finally
determined, the portion of the Gross-Up Payment attributable to such reduction
(plus that portion of the Gross-Up Payment attributable to the Excise Tax and
federal, state and local income tax imposed on the Gross-Up Payment being repaid
by the Employee to the extent that such repayment results in a reduction in
Excise Tax and/or a federal, state or local income tax deduction) plus interest
on the amount of such repayment at the rate provided in section 1274(b)(2)(B) of
the Code. In the event that the Excise Tax is determined to exceed the amount
taken into account hereunder at the time of the termination of Employee's
employment (including by reason of any payment the existence or amount of which
cannot be determined at the time of the Gross-Up Payment), Zenith shall make an
additional Gross-Up Payment in respect of such excess (plus any interest,
penalties or additions payable by the Employee with respect to such excess) at
the time that the amount of such excess is finally determined.

                  11.5 The payments provided for in Paragraphs 11.2 (other than
subparagraph 11.2(iii)) and 11.4 hereof shall be made not later than the fifth
day following the date of termination of employment, provided, however, that if
the amounts of such payments cannot be finally determined on or before such day,
Zenith shall pay to Employee on such day an estimate, as determined in good
faith by Zenith, of the minimum amount of such payments to which Employee is
clearly entitled and shall pay the remainder of such payments (together with
interest at the rate provided in section 1274(b)(2)(B) of the Code) as soon as
the amount thereof can be determined but in no event later than the thirtieth
(30th) day after the date of termination of employment. In the event that the
amount of the estimated payments exceeds the amount subsequently determined to
have been due, such excess shall constitute a loan by Zenith to Employee,
payable on the fifth (5th) business day after demand by Zenith (together with
interest at the rate provided in section 1274(b)(2)(B) of the Code). At the time
that payments are made under this Paragraph, Zenith shall provide Employee with
a written statement setting forth the manner in which such payments were
calculated and the basis for such calculations including, without limitation,
any opinions or other advice Zenith has received from outside counsel, auditors
or consultants (and any such opinions or advice which are in writing shall be
attached to the statement).

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11A.     POST-RETIREMENT CONSULTING AGREEMENT. Notwithstanding anything in this
agreement to the contrary, in the event Employee's employment with the Employer
is terminated (i) pursuant to Sections 10.2 or 11.2 of this Agreement or (ii)
upon expiration of the Term of Employment, such termination shall be deemed to
be by reason of his retirement and Employee and the Company shall enter into a
consulting agreement substantially in the form attached hereto effective as of
the date of such retirement. Except as necessary in order to avoid duplication
of benefits (e.g., in connection with the provision of health care benefits) the
benefits provided under the consulting agreement shall be in addition to and not
in lieu of the benefits (including severance benefits) otherwise provided under
this Agreement.

12.      ATTORNEY'S FEES. In the event that any action at law or in equity, for
injunctive or declaratory relief, is brought to enforce or interpret the
provisions of this Agreement, if Employee is the prevailing party, he shall be
entitled to reasonable attorney's fees in addition to any other relief to which
he may be entitled.

13.      APPLICABLE LAW. This Agreement and the rights and obligations of the
parties hereunder shall be construed, interpreted and enforced in accordance
with, and governed by, the laws of the State of California applicable to
agreements executed and fully to be performed thereunder.

14.      NOTICES. Any notice required to be given hereunder shall be in writing
sent by registered or certified mail, return receipt requested, to either Zenith
or employee at the addresses listed below, or at such other addresses as either
Zenith or Employee may hereafter designate in writing to the other:

         To Zenith:          Zenith National Insurance Corp.
                             21255 California Street
                             Woodland Hills, California 91367
                             Attention:  Corporate Secretary

         To Employee:        813 North Bedford Drive
                             Beverly Hills, California 90210

15.      ASSIGNMENT.

                  15.1 This Agreement and the rights, interests, and benefits
hereunder are personal to Employee and shall not be assigned, transferred,
pledged, or hypothecated in any way by Employee, and shall not be subject to
execution, attachment or similar process. Any attempted assignment, transfer,
pledge, or hypothecation, or the levy of any execution, attachment or similar
process thereon, shall be null and void and without effect.

                  15.2 Zenith shall have the right to assign this Agreement and
to delegate all of its rights, duties and obligation hereunder, whether in whole
or in part, to any parent, affiliate, successor, or subsidiary organization or
company of Zenith or corporation with which Zenith may merge or consolidate or
which acquires by purchase

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or otherwise all or substantially all of Zenith's consolidated assets, but such
assignment shall not release Employer from its obligations under this Agreement,
and in the event of any such assignment by Zenith, Employee may, at his sole
option, exercise his termination rights under the provisions of Paragraph 11 of
this Agreement.

16.      ENTIRE AGREEMENT. This Agreement constitutes the entire understanding
of the parties hereto and supersedes any and all prior agreements and
understanding whether oral or written between the parties. This Agreement may
only be modified by an agreement in writing executed by one of Zenith's duly
authorized officers (other than Employee), with the approval of Zenith's Board
of Directors, and by Employee.

17.      WAIVER OF BREACH. The waiver by Employee of a breach of any provision
of this Agreement by Employee shall not operate or be construed as a waiver of
any subsequent breach by Employee.

18.      MISCELLANEOUS.

                  18.1 The titles of the paragraphs of this Agreement are for
convenience of reference only, and are not to be considered in construing this
Agreement.

                  18.2 The unenforceability or invalidity of any paragraph or
subparagraph of this Agreement shall not affect the enforceability and validity
of the balance of this Agreement.

                  18.3 Each party hereto shall make, execute and deliver such
other instruments or documents as may be reasonable required in order to
effectuate the purpose of this Agreement.

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         IN WITNESS WHEREOF, the parties hereto have executed this Agreement in
Woodland Hills, California, on the date indicated below.

                                       ZENITH NATIONAL INSURANCE CORP.
                                       ("Zenith")

                                       By:      /s/ Bill Owen
                                       As agent for and on behalf of Zenith
                                       and each and all of its subsidiaries
                                       ("Employer")

                                       Date:   3/13/01

                                       By:      /s/ Stanley R. Zax
                                       STANLEY R. ZAX ("Employee")

                                       Date:   3/13/01

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                 [FORM OF] POST-RETIREMENT CONSULTING AGREEMENT

         This POST-RETIREMENT CONSULTING AGREEMENT (the "Agreement") is entered
into as of the date set forth below by and between Zenith National Insurance
Corp., a Delaware corporation ("Company"), and Stanley R. Zax ("Consultant").

         WHEREAS, Company acknowledges that Consultant has unique talents,
knowledge and information that will be valuable to the Company in connection
with the management of the Company following Consultant's retirement and
believes that it would be in the best interests of the stockholders of the
Company following such retirement to continue to secure the services of
Consultant during the period of this Agreement; and

         WHEREAS, Company and Consultant acknowledge and understand the terms
and conditions of the retention of Consultant as set forth herein, including the
condition that Consultant agree to adhere to each of the various covenants and
agreements contained herein and in consideration of the Company's establishing a
consulting relationship with Consultant, providing Consultant with continuing
compensation for the purposes and in the manner set forth herein, Consultant has
decided to enter into, and agree to be bound by, this Agreement.

         NOW, THEREFORE, in consideration of the premises and the respective
covenants and agreements of the parties herein contained, and intending to be
legally bound hereby, the parties hereto agree as follows:

         1.       ENGAGEMENT AS CONSULTANT. The Company hereby engages
Consultant, and Consultant hereby agrees to serve the Company, as an independent
contractor, on the terms and conditions set forth herein.

         2.       CONSULTING PERIOD. The term (the "Term") of this Agreement
shall commence on the date Consultant ceases to be an employee of the Company
for any reason (other than death or Disability as defined in this Agreement) on
or after his attainment of age 65 (the "Effective Date") and shall expire at the
close of business on the fifth (5th) anniversary thereof (such expiration date
being hereinafter referred to as the "Termination Date"), unless earlier
terminated in

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accordance with Section 6 hereof; provided, that the provisions set forth in
Sections 7 through 9 hereof shall remain in full force and effect for the Term.

         3.       DUTIES. During the Term, Consultant will make himself
available to the Company and shall provide such consulting services to the
Company as the Board of Directors of the Company or the Chief Executive Officer
of the Company may from time to time request. Except as the parties may
otherwise agree, for each twelve-month period during the Term commencing on the
Effective Date, Consultant shall not be required to provide consulting services
in excess of the following:

                       Year 1  -   100 hours per quarter
                       Year 2  -   75 hours per quarter
                       Year 3  -   50 hours per quarter
                       Year 4  -   25 hours per quarter
                       Year 5  -   10 hours per quarter

         4.       PLACE OF PERFORMANCE. Consultant may provide his consulting
services hereunder by telephone consultation, written communication and/or fax
as appropriate or at such locations as are acceptable to the Company; provided,
however, Consultant shall not, without his prior consent, be required to render
such services at any location more distant than thirty (30) miles from his
residence or his principal place of business.

         5.       COMPENSATION AND RELATED MATTERS. As compensation for the
services to be rendered by the Consultant hereunder, the Company shall make the
following payments and provide the following benefits to the Consultant:

                  (a)      CONSULTING FEE. As compensation for the services to
be rendered by Consultant herein, the Company shall pay Consultant an annual fee
in the following amounts, which amount shall be paid in accordance with the
Company's normal payroll policy (the "Consulting Fee"):

                       Year 1  -   $750,000
                       Year 2  -   $600,000
                       Year 3  -   $500,000
                       Year 4  -   $400,000
                       Year 5  -   $300,000

                                       2
<PAGE>

                  (b)      REIMBURSEMENT OF EXPENSES. During the Term, the
Company shall provide Consultant with (i) an office located in Los Angeles and
commensurate in size and stature with the office provided to him pursuant to his
employment with the Company as the Chairman of the Board, President and Chief
Executive Officer, which office shall be subject to the approval of Consultant,
(ii) a secretary, (iii) a car allowance in accordance with the Company's policy
with respect to senior executive officers of the Company, and (iv) continued
coverage under the Company's health insurance in accordance with the Company's
policy with respect to senior executive officers of the Company. The Company
shall reimburse Consultant for reasonable and necessary business expenses of
Consultant incurred in connection with the performance of Consultant's duties,
and which are consistent with such guidelines as the Company may from time to
time establish with respect to senior executive officers of the Company. All
payments for reimbursement of such expenses shall be made to Consultant upon the
presentation to the Company of appropriate receipts or other documentation in
accordance with the Company's normal reimbursement procedures.

         6.       TERMINATION. Upon termination of Consultant's engagement on
the Termination Date (unless earlier terminated pursuant to this Section 6),
this Agreement shall terminate, and the Company shall have no further obligation
to Consultant except as set forth herein.

                  (a)      TERMINATION BY THE COMPANY OTHER THAN FOR CAUSE,
DEATH OR DISABILITY. The Company shall not be entitled to terminate this
Agreement or terminate the services of Consultant at any time other than for
Cause (defined below) or due to Consultant's death or Disability (as defined
below). In the event the Company terminates this Agreement for any reason other
than for Cause or due to Consultant's death or Disability, the Company shall
continue to provide Consultant with all the benefits set forth in the Agreement
through the Term of the Agreement.

                  (b)      TERMINATION FOR CAUSE, DEATH, DISABILITY, OR BY
CONSULTANT FOR ANY REASON. The Company shall be entitled to terminate this
Agreement at any time for Cause or due to Consultant's death or Disability. The
Consultant may terminate this Agreement only upon 90 days notice. In the event
of termination of this Agreement by the Company for Cause or due to Consultant's
death or by Consultant, Consultant (or his estate) shall be entitled to payment
of any earned but unpaid Consulting Fee accrued through such termination;
provided, however, in the event that Consultant fails or refuses to perform
services under this Agreement (or, in the event of

                                       3
<PAGE>

a Consultant's breach of any or all of the covenants and agreements contained
herein), the Company's obligations pursuant to this Agreement shall terminate.
Following any such termination, Consultant shall not be entitled to receive any
Consulting Fee or other payment provided for hereunder other than earned but
unpaid Consulting Fees through the date of such termination. Notwithstanding
anything herein to the contrary, in the event of termination of this Agreement
by the Company due to Consultant's Disability, the Company shall continue to
provide Consultant with all the benefits set forth in the Agreement through the
Term of the Agreement.

                  (c)      DEFINITIONS.

                           (1)      "Cause" shall mean Consultant's breach of
any of his material obligations under this Agreement.

                           (2)      "Disability" shall mean Consultant is
determined by the Board of Directors to be physically or mentally incapacitated
such that he is unable to perform the services required to be performed under
this Agreement.

         7.       SEVERABILITY. If any provision of this Agreement is determined
to be invalid or unenforceable, such provision shall be construed to be
enforceable to the full extent permitted by law. In any event, the validity and
enforceability of the other provisions of this Agreement shall not be affected.

         8.       NOTICES. All notices and other communications under this
Agreement shall be in writing and shall be given by fax or first class mail,
certified or registered with return receipt requested, and shall be deemed to
have been duly given three (3) days after mailing or twenty-four (24) hours
after transmission of a fax to the respective persons named below:

         If to Company:      Zenith National Insurance Corp.
                             21255 Califa Street
                             Woodland Hills, California 91367
                             Attention:  Corporate Secretary

         If to Consultant:   813 North Bedford Drive
                             Beverly Hills, California 90210

                                       4
<PAGE>

         Either party may change such party's address for notices by notice duly
given pursuant hereto.

         9.       ATTORNEY'S FEES. In the event that nay action at law or in
equity, for injunctive or declaratory relief, is brought to enforce or interpret
the provisions of this Agreement, if Consultant is the prevailing party, he
shall be entitled to reasonable attorney's fees in addition to any other relief
to which he may be entitled.

         10.      GOVERNING LAW. This Agreement and the rights and obligations
of the parties hereunder shall be construed, interpreted and enforced in
accordance with, and governed by, the laws of the state of California applicable
to agreements executed and fully to be performed thereunder.

         11.      ENTIRE AGREEMENT; MODIFICATION; WAIVER. This Agreement (along
with the employment agreement of which it is a part) constitutes the entire
understanding between the parties hereto regarding the subject matter hereof,
and may not be modified without the express written consent of the parties. This
Agreement supersedes all prior written and/or oral and all contemporaneous oral
agreements, understandings and negotiations regarding the subject matter hereof.
This Agreement and Consultant's rights and obligations hereunder may not be
modified, released, terminated or waived, in whole or in part, except by an
instrument in writing signed by an executive officer of the Company. The
Company's failure to assert, delay in asserting, or waiver of any right or
remedy under this Agreement shall not impair, waive, or otherwise affect such
right or remedy, or any other right or remedy.

         12.      ASSIGNMENT. This Agreement shall be binding upon Consultant
and Consultant's heirs, executors, personal representatives, and successors and
assigns. Consultant's duties and obligations under this Agreement shall not be
assigned without the Company's prior written approval of such assignment. The
Company shall have the right freely to assign this Agreement in its sole
discretion and without Consultant's prior approval of such assignment.

         13.      VOLUNTARY AGREEMENT. Consultant acknowledges and agrees that,
prior to signing this Agreement, Consultant (i) received a copy of this
Agreement, read such Agreement, and understood each of the terms and conditions
of such Agreement; and (ii) had sufficient opportunity to consult with legal
counsel of

                                       5
<PAGE>

Consultant's choice prior to signing this Agreement. Consultant represents and
warrants that Consultant does not rely and have not relied on any fact,
representation, statement or assumption other than as specifically set forth in
this Agreement, and Consultant enters into this Agreement freely, voluntarily,
and without coercion.

         14.      INDEPENDENT CONTRACTOR. During the Consulting Period,
Consultant shall be an independent contractor and not an employee of the Company
and except as set forth herein, is not entitled to the benefits provided by the
Company or its affiliates to its employees as an employee, including but not
limited to coverage under any tax-qualified retirement plan. Accordingly,
Consultant shall be responsible for payment of all taxes, including Federal and
State income tax, Social Security tax, Unemployment Insurance tax and any other
taxes or business license fees as required by virtue of Consultant's activities
hereunder.

         15.      COUNTERPARTS. This Agreement may be executed in counterparts,
each of which shall be deemed to be an original but all of which together shall
constitute one and the same instrument.

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement in
Woodland Hills, California, on the date indicated below.

                                       ZENITH NATIONAL INSURANCE CORP.
                                       ("Company")

                                                       FORM ONLY
                                       By:
                                          --------------------------------------
                                       As agent for and on behalf of the Company
                                       and each and all of its Subsidiaries

                                       Date:
                                            ------------------------------------

                                                        FORM ONLY
                                       By:
                                          --------------------------------------
                                          STANLEY R. ZAX ("Consultant")

                                       Date:
                                            ------------------------------------

                                       6\<PAGE>

                                                                     EXHIBIT 4.1

                       AMENDMENT NO. 2 TO RIGHTS AGREEMENT

         This Amendment No. 2 dated as of March 20, 2001 hereby amends the
Rights Agreement dated as of January 26, 1998, as amended by Amendment No. 1
dated as of February 17, 1999 (the "Agreement"), between Open Market, Inc., a
Delaware corporation (the "Company"), and Fleet National Bank (formerly known as
BankBoston N.A.), a national banking association, as Rights Agent (the "Rights
Agent").

                              W I T N E S S E T H:

         WHEREAS, no Stock Acquisition Date, as such term is defined in the
Agreement, has occurred; and

         WHEREAS, the Company has directed the Rights Agent to enter into this
Amendment No. 2 pursuant to Section 27 of the Agreement;

         NOW, THEREFORE, in consideration of the premises and mutual agreements
set forth herein, the parties hereby agree as follows:

1.       Section 1(a) of the Agreement is hereby deleted in its entirety and the
         following is substituted in lieu thereof:

                  (a) "Acquiring Person" shall mean any Person who or which,
together with all Affiliates and Associates of such Person, shall be the
Beneficial Owner of 18% or more of the shares of Common Stock then outstanding,
but shall not include (i) the Company, (ii) any Subsidiary of the Company, (iii)
any employee benefit plan of the Company or of any Subsidiary of the Company,
(iv) any Person or entity organized, appointed or established by the Company for
or pursuant to the terms of any such plan or (v) an Exempted Person.
Notwithstanding the foregoing, no Person shall become an "Acquiring Person" as
the result of an acquisition of Common Stock by the Company which, by reducing
the number of shares outstanding, increases the proportionate number of shares
beneficially owned by such Person to 18% or more of the Common Stock of the
Company then outstanding; PROVIDED, HOWEVER, that if a Person shall become the
Beneficial Owner of 18% or more of the Common Stock of the Company then
outstanding by reason of share purchases by the Company and shall, after such
share purchases by the Company, become the Beneficial Owner of any additional
Common Stock of the Company, then such Person shall be deemed to be an
"Acquiring Person." Notwithstanding the foregoing, if the Board of Directors of
the Company determines in good faith that a Person who would otherwise be an
"Acquiring Person," as defined pursuant to the foregoing provisions of this
paragraph (a), has become such inadvertently, and such Person divests as
promptly as practicable a sufficient number of shares of Common Stock so that
such Person would no longer be an "Acquiring Person," as defined pursuant to the
forgoing provisions of this paragraph (a), then such Person shall not be deemed
to be an "Acquiring

<PAGE>

Person" for any purposes of this Agreement unless and until
such Person shall again become an "Acquiring Person."

2. Section 1 of the Agreement is hereby further amended by adding new paragraph
(ii) at the end thereof, as follows:

                  (ii) "Exempted Person" shall mean The Palladin Group, L.P. and
Gleneagles Fund Company, and each of their respective Affiliates and Associates
(collectively, "the Palladin Entities"), unless and until such time as the
Palladin Entities directly or indirectly become the Beneficial Owner of Common
Stock in excess of the Exempt Threshold. For purposes of this Agreement, the
Exempt Threshold shall mean that percentage of the Common Stock equal to the sum
of that percentage of shares of Common Stock then outstanding represented by
shares received (A) as a dividend on or as a result of any conversion or
redemption of, shares of the Company's Series E 6% Cumulative Convertible
Preferred Stock, $.10 par value per share, (B) pursuant to the Purchase
Agreement, dated the date hereof, between the Company and certain of the
Palladin Entities, and the agreements referred to therein including the
Registration Rights Agreement, the Common Stock Warrant and the Adjustment
Warrant, each dated the date hereof or (C) pursuant to the Common Stock Purchase
Agreement, dated the date hereof, between the Company and Gleneagles Fund
Company.

3. Section 11(a)(ii) of the Agreement is hereby deleted and the following is
substituted in lieu thereof:

                  (a)(ii) Subject to Section 24 of this Agreement, in the event
that any Person shall become an Acquiring Person, unless the event causing the
18% threshold (or, in the case of an Exempted Person, the Exempt Threshold) to
be crossed is a transaction set forth in Section 13(a) hereof, then, promptly
following the first occurrence of such event, proper provisions shall be made so
that each holder of a Right (except as provided below and in Section 7(e)
hereof) shall thereafter have the right to receive, upon exercise thereof at the
then current Purchase Price in accordance with the terms of this Agreement, in
lieu of a number of one one-thousandths of a share of Preferred Stock, such
number of shares of Common Stock of the Company that equals the result obtained
by (x) multiplying the then current Purchase Price by the then number of one
one-thousandths of a share of Preferred Stock for which a Right was exercisable
immediately prior to the first occurrence of a Section 11(a)(ii) Event, and (y)
dividing that product (which, following such first occurrence, shall thereafter
be referred to as the "Purchase Price" for each Right and for all purposes of
this Agreement) by 50% of the current market price (determined pursuant to
Section 11(d) hereof) per share of Common Stock on the date of such occurrence
(such number of shares, the "Adjustment Shares").

         IN WITNESS WHEREOF, the parties have caused this Amendment No. 2 to be
duly executed and their respective corporate seals to be hereunto affixed and
attested as of the day and year first written above.

                                       2

<PAGE>

                                            OPEN MARKET, INC.
Attest:

/s/ Edward Durkin                        By: /s/ Harland LaVigne
---------------------------------------     -------------------------------
Name:  Edward Durkin                        Name:  Harland LaVigne
Title: Chief Financial Officer              Title: Chairman of the Board
                                                   and Chief Executive Officer
      Seal

                                            FLEET NATIONAL BANK
Attest:

/s/ Vina LaFontant                          By:/s/ Carol Mulvey-Eori
--------------------------------------         ---------------------------------
Name: Vina LaFontant                           Name: Carol Mulvey-Eori
Title: Account Manager                         Title: Directing Manager

         Seal

                                       3

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