** Shares of online travel firm Tripadvisor TRIP.O rise 5% to $15.73 premarket following a Wall Street Journal report that activist investor Starboard Value has built an over 9% stake in co
** Starboard likely to disclose stake in a regulatory filing as soon as Thursday, says WSJ
** Stake is valued at roughly $160 mln
** Co last year formed a special committee to explore potential sale, but determined it was against co's best interests
** Four brokerages rate the stock "buy" and higher, 10 "hold" and five "sell" and lower; median PT is $16.63 - data compiled by LSEG
** As of last close, stock is up 1.49% YTD, while peers Booking Holdings BKNG.O is up 14.7%, Airbnb ABNB.O is up 3% and Expedia EXPE.O is down 8.2%
(Reporting by Ankita Yadav in Bengaluru)
((Ankita.Yadav@thomsonreuters.com;))