Electronic Arts will soon start selling games made by its competitors.
The company's new Origin platform for digital distribution will offer games from Warner, THQ and Capcom with the first first games out next month.
Batman: Arkham City and Saints Row: The Third are two of the triple-A games destined for the service.
EA says having more publishers use its rival to platforms such as Steam add "to the extensive library of more than 100 EA PC games already available, and giving PC gamers even more choice for the latest and greatest gaming content on Origin".
"Since launch, we've had overwhelming support from both publishers and developers across the gaming industry, recognising Origin as an opportunity to deliver more of their great content straight to consumers across the globe," said David DeMartini, senior vice president of Origin at EA.
"We're excited to welcome Warner Bros. Interactive Entertainment, THQ and Capcom as the first publishers to offer their games via Origin."
The full list of games of games on offer is still to be published, however, with EA's statement saying it will offer "some" games from these partners - but this is still a first step in beefing up the Origin platform and putting pressure on market-leader Steam.
Earlier this year contract and DLC disputes saw EA games taken off Steam as the publisher and developer Valve disagreed on how content should be sold to consumers.
EA says Origin already has six million registered users - recently the service added live streaming demos, free-to-play games and cloud storage alongside traditional download and social elements.
The firm published testimonials from its three rivals-turned-partners with today's announcement:
"We are very pleased to partner with EA and have Warner Bros. Interactive Entertainment's key PC titles available on Origin," said Greg Ballard, senior vice president, Digital Games, Warner Bros. Interactive Entertainment. "In growing our digital offerings for consumers we want to give fans increased access to critically acclaimed titles such as Batman: Arkham City."
"THQ is excited to work with Origin and to offer players another new, innovative way to experience the over-the-top fun of Saints Row: The Third," said Terri Schiek, senior vice president of publishing, Americas at THQ. "We look forward to building our relationship with the Origin team, and to continue to deliver great content for the platform."
"When we met with the EA team and discussed their long-term vision for Origin, we were excited to lend our weight to their efforts," said Christian Svensson, senior vice president at Capcom Entertainment. "We hope to expand our PC fanbase for our legendary brands on Origin."