** Shares of contract research firm Charles River Laboratories CRL.N rise 4.80% to $120.95 premarket

** Co has reached a settlement with activist investor Elliott Investment Management to add four new directors to its board and launch a strategic review of the business, Reuters reports, citing two sources familiar with the matter

** Elliott's Global Head of Engagement Steven Barg will join the board along with three other independent directors who have expertise in the pharmaceutical industry, the report adds

** Elliott has become the largest investor in Charles River, but its exact stake could not be determined, according to the report

** The agreement could be announced as early as Wednesday when the co is set to report its quarterly results, the sources told Reuters

** Up to last close, stock was down 38% YTD

(Reporting by Sriparna Roy in Bengaluru)

((Sriparna.Roy@thomsonreuters.com;))