FIRST AMENDMENT TO ZENITH NATIONAL INSURANCE CORP. AMENDED AND RESTATED EXECUTIVE OFFICER BONUS PLAN

Exhibit 10.17

FIRST AMENDMENT

TO

ZENITH NATIONAL INSURANCE CORP.

AMENDED AND RESTATED EXECUTIVE OFFICER BONUS PLAN

Zenith National Insurance Corp., a Delaware corporation (the “Company”), hereby amends the Zenith National Insurance Corp. 2003 Amended and Restated Executive Officer Bonus Plan (the “Plan”), effective December 1, 2008, with reference to the following:

WHEREAS, the Company maintains the Plan for the benefit of its executive officers; and

WHEREAS, the Plan was amended and restated on February 12, 2003; and

WHEREAS, Section 409A of the Internal Revenue Code of 1986, as amended (the “Code”), places certain restrictions, among other things, as to the timing of distributions from nonqualified deferred compensation plans and arrangements; and

WHEREAS, the Board of Directors of the Company desires to amend the Plan to comply with Section 409A of the Code; and

WHEREAS, the Compensation Committee of the Company has previously granted the appropriate officers of the Company the authority to prepare such amendments as may be necessary in order to comply with Section 409A of the Code;

NOW THEREFORE, the Plan is hereby