X0202 4 2004-10-20 1 0001169358 INVERESK RESEARCH GROUP INC IRGI 0001226486 COWAN D J PAUL E 11000 WESTON PARKWAY CARY NC 27513 0 1 0 0 CFO and Treasurer Option to Purchase Common Stock 0.398 2004-10-20 4 D 0 143000 D 2002-06-28 2012-03-25 Common Stock 143000 0 D Option to Purchase Common Stock 23.64 2004-10-20 4 D 0 35000 D 2004-10-20 2004-01-30 Common Stock 35000 0 D Option to Purchase Common Stock 17.75 2004-10-20 4 D 0 20000 D 2004-10-20 2013-06-28 Common Stock 20000 0 D These options were originally exercisable through the date specified. However, pursuant to the terms of Inveresk's Amended and Restated 2002 Stock Option and Incentive Compensation Plan, Paul Cowan will only have until January 20th, 2005 to exercise the Charles River stock options he receives in exchange for his Inveresk stock options. Paul Cowan received Charles River stock options in exchange for his Inveresk stock options pursuant to the Agreement and Plan of Merger dated as of June 30, 2004, by and among the Issuer, Charles River Laboratories International, Inc., Indigo Merger I Corp. and Indigo Merger II Corp. The options originally were not due to begin vesting until 1/30/2005. However, full vesting was accelerated to October 20, 2004 pursuant to the terms of Paul Cowan's Change of Control Agreement. The options originally began to vest one third after one year after grant (or one third on June 28, 2004), the next third after two years from the date of grant and the final third after three years. However, full vesting was accelerated to October 20, 2004 pursuant to the terms of Paul Cowan's Change of Control Agreement. /s/ Martha Boyd as attorney in fact for D.J. Paul E. Cowan 2004-10-20