LOS ANGELES -- Microsoft ( MSFT) is bringing out the big guns to lure consumers to its Xbox 360 platform. The catch? Consumers will have to wait until next year. At a media event here in advance of the E3 video-game conference, the software giant announced that new versions of Grand Theft Auto and Halo -- two of the industry's biggest game franchises -- will be coming to the Xbox 360 in 2007. Grand Theft Auto IV, published by Take-Two Interactive ( TTWO), will hit store shelves in October next year. Microsoft did not give a specific date for Halo 3. "We couldn't be more excited to have this available on our platform from day one" of its release, said Peter Moore, Microsoft's corporate vice president in charge of its video-game businesses. The agreement with Take-Two represents something of a coup for Microsoft. For previous iterations of GTA, Sony ( SNE), the industry's biggest player, secured exclusive releases that ensured the games were not available on any other platform until months or years after they were released on Sony's PlayStation game systems. That's worked out very well for Sony. The latest iteration of the series, Grand Theft Auto: Liberty City Stories has been one of the top-selling titles for Sony's PlayStation Portable game system. Meanwhile, Grand Theft Auto III is considered to have been the key game that drove sales of the PlayStation 2. Microsoft won't have Grand Theft Auto IV exclusively for Xbox 360; instead, it will get it on the same date that Take-Two will release the game for the PlayStation 3. But even having it on the same day should blunt some of Sony's advantage. Take-Two, for instance, didn't release Grand Theft Auto: San Andreas for the original Xbox until months after it released a version for Sony's PlayStation 2. By then, Take-Two had already sold millions of copies of the game.