The news comes following the announcement last week that Square had made an offer to buy the ailing Britsoft firm.
Time Warner owns a 20 per cent stake in Eidos, and although it was often seen as one of the frontrunners alongside Squre to buy the publisher, it would have had to accept the bid or place a higher bid itself.
But this morning Warner and Square Enix announced that the former has 'irrevocably' agreed to support the Japanese publisher's plans to takeover Eidos.
MCV predicted last year that the firm was a surprise contender to buy Eidos - other spectators regularly put EA and Ubisot in the frame.
Square Enix, through its dealings with the management and now Time Warner, has the backing of shareholders responsible for 35 per cent of Eidos stock. The firm's board is to vote on the final acquisition at the end of March, but with so much momentum behind the buy already - and Eidos management's pledge to fully back the acquisition - it seems unlikely they will vote against it.
Square's bid last week was estimated at around £84m - around 129 per cent Eidos' market value.
The current bid could still fall through, should Square Enix fail to post the scheme details for its planned takeover of Eidos or a third party step forward to make an alternative bid. Both are unlikely at this stage - Eidos has been courting various buyers on and off over the last year.
Eidos products cover a raft of genres with Western appeal, something Square Enix has been vocally seeking for the past two years. Its slate of studios and IP would complement Square’s activity and plug the gaps in its line-up.