** Shares of drug developer Metsera MTSR.O fall 3.1% to $61.13 after Pfizer PFE.N files a second lawsuit against co and Novo Nordisk NOVOb.CO
** Co's shares hit a record high last week following counter-bid from Novo Nordisk after Pfizer already locked in a deal with it valued at about $7.3 bln
** PFE accusesn MTSR of anticompetitive conduct
** PFE says it is taking the action to "enforce and preserve its rights under the merger agreement"
** PFE filed a lawsuit against MTSR on Friday for breaching the agreement, which the drug developer had disagreed with
** PFE received approval from the U.S. Federal Trade Commission on Friday for proposed buyout of MTSR
** MTSR shares have gained more than double after listing in January
(Reporting by Utkarsh Tushar Hathi)
((utkarshtushar.hathi@thomsonreuters.com))