Time Warner has purchased ten million shares in Eidos PLC, bringing its total stake in the company up to over 19 per cent.
The Warner Bros parent now owns 52.52 million shares in the UK publisher, which was previously known as SCi Entertainment.
Sources have long pointed to Warner as a likely buyer of Eidos, which offers an IP slate including Tomb Raider, Hitman and Championship Manager.
However, Square Enix emerged as an unlikely challenger this month, when boss John Yamamoto visited Eidos studio IO in Denmark.