** Shares of UK gaming firm PlaytechPTEC.L down 3.4% at 379p
** Swedish online gaming firm Evolution EVOG.ST files to add Playtech as a defendant in ongoing defamation lawsuit against Calcagni & Kanefsky LLP and Black Cube
** Evolution alleges that Playtech worked to damage its reputation to eliminate competition in the North American market
** Filing also accuses Playtech of trade libel, fraud, and racketeering, and of withholding information about its conduct from shareholders
** YTD the stock has gained 34.4%
(Reporting by Raechel Thankam Job in Bengaluru)
((RaechelThankam.Job@thomsonreuters.com))