Microsoft said on Tuesday it will release its "Halo 3" video game on September 25, a hugely anticipated event that the software giant hopes will help drive sales of its Xbox 360 gaming console. "Halo 3" is the final installment of Microsoft's flagship video game franchise in which players assume the role of a futuristic soldier trying to turn the tide in a war against an alien army.

The game is expected to be a potent weapon for Microsoft as it fights Sony and Nintendo for dominance in the $30 billion global video game industry.

By moving up the launch of "Halo 3" to the month of September, Microsoft is betting it will spur sales of Xbox 360 consoles, giving it a larger user base in time for the year-end holiday season that is the high tide for video game sales.

"This is going to be a critical holiday for us versus Sony, especially on the console generation side, and they don't really have an answer for 'Halo 3'," Shane Kim, head of Microsoft Game Studios, said in an interview.

"Given that, I suspect 'Halo 3' to drive a lot of Xbox 360 sales and Xbox Live memberships," Kim said. "I think at those midnight (launch) events, there are going to be a lot of people walking out with an Xbox 360 along with their copies of 'Halo 3'."

The game will go on sale in Europe on September 26 but Kim said Microsoft had not set a date for Japan, where the Xbox 360 has been eclipsed by Nintendo's Wii and Sony's PlayStation 3.

The regular edition of "Halo 3" will sell for $60, with two limited editions going for $70 and $130.