AT&T announced an agreement with social games market leader Zynga, which the operator said is “designed to bring the very latest in mobile social gaming to AT&T’s millions of wireless customers.” The partnership is described as “the first of its kind between Zynga and a US wireless carrier.” Games including Words with Friends and Zynga Poker, plus “customised content,” will be available for download via “AT&T’s shelf in Android Market” later this year. Terms of the agreement were not revealed.

In addition to offering additional content within online and mobile social games, AT&T customers will also get access to free credits in select games. As part of the relationship, the operator will “work closely with Zynga to optimise the mobile gaming experience for AT&T customers,” stating that “having already tested several games across a range of AT&T Android devices, the companies will continue to explore ways to extend device battery life during game play, as well as improve network efficiency for playing.”

According to the Wall Street Journal, Zynga is set for an initial public offering that values it at “as high as US$20 billion,” twice the valuation it achieved “just a few months ago” when it sold shares to venture capitalists. It said that the company had revenue of around US$850 million last year, “roughly the same as the two biggest video game publishers – Electronic Arts and Activision Blizzard – combined.” The company has built its business on offering games for Facebook, but in line with many of its competitors it is looking to integrate mobile with its social gaming properties.