IGN.com reports that Activision Blizzard, publisher of hit games such as Guitar Hero, Call of Duty, World of Warcraft and Starcraft, has canceled its membership in the Entertainment Software Association, and won't be part of ESA's E3 event this year.

May 2, 2008 - Updated: Activision Blizzard has canceled its membership in the Entertainment Software Association and will not be participating in the trade group's official E3 event in Los Angeles this year.

The publishing giant will not have a presence on the E3 show floor and will hold its own off-site press event on the first night of the conference instead.

"After careful consideration, Activision has decided not to renew its ESA membership for business reasons and will not be participating in any official E3 activities," Activision told IGN in a written statement. "We appreciate the work that the ESA has done over the years in promoting the interactive entertainment industry with state and federal governments and wish the ESA best of luck with the show."

Although Activision is out, other large third-party publishers and first-party platform holders told IGN they are still committed to participating in E3, although the companies we spoke with today declined to elaborate on the extent of their planned involvement.

"EA is fully committed to ESA and E308," said Holly Rockwood, Electronic Arts' director of corporate communications. "We're confident that a critical mass of developers, publishers and console manufacturers will be on hand to put on an exciting event this summer."

Sony and Microsoft representatives told IGN they plan to participate in E3 this year, but both companies declined to answer specific questions about the conference's shifting role in an industry that is both expanding in scope and seeing increased consolidation among developers and publishers.

E3 has gone through a number of changes in recent years. What was once a large-scale free-for-all has become a smaller, more focused affair with attendance limited to invitees. In 2007, the event moved from the Los Angeles Convention Center to Santa Monica. This year's show, scheduled to run from July 15-17, is back at LACC.