** Shares of clinical laboratory operator  LH.N  up 2.9% at
$251 
    ** Activist investor Jana is said to nominate directors to
co's board, according to tweet by Bloomberg reporter 
    ** According to regulatory filing on Feb. 16, Jana Partners
bought 811,661 shares in Labcorp, making it one of the firm's
five largest investments
    ** Jana, founded by Barry Rosenstein, has a history of
pushing for change in healthcare space  
    ** Including session's gain, stock had risen ~34% in last 12
months

 (Reporting by Dania Nadeem in Bengaluru)
 ((Dania.Nadeem@thomsonreuters.com;))