General Motors has signed on as a larger sponsor of Fox’s "X Factor," becoming the second major advertiser to pledge support for the much-anticipated musical-contest program, according to people familiar with the situation.

Spokespeople for Fox and General Motors declined to comment.

The sponsorship will likely weave a GM vehicle into epsiodes of "X Factor," but will not last the entire season, like the deals that Coca-Cola, Ford Motor and AT&T have with Fox’s other big program, "American Idol." Last January, Pepsi said it would be exclusive season-long sponsor of the program, which Fox executives are hoping will match ratings juggernaut "Idol" in terms of viewer interest.

With TV networks in the midst of selling their fall ad inventory, part of the process known as the "upfront," the new Fox show is getting major interest from marketers. While it’s often true that more than three-quarters of new TV programs fail, "X Factor" is already a success overseas and is going after the broader family audience that tunes in to "American Idol." As such, some marketers are treating "X Factor" as if it’s a sure thing.

General Motors has been aggressive on the TV-advertising front in the past year, weaving various Chevrolet vehicles into CBS’s "Hawaii Five-0" and enjoying rather obvious integration into the scenes and plots of "Men of a Certain Age" on Time Warner’s TNT. The "X Factor" sponsorship will likely focus on one of the company’s auto brands, and will not burnish the larger corporation, according to a person familiar with the matter.

The number of "X Factor" episodes in which GM will be involved could not be determined. One person familiar with the matter suggested the car company’s plans for the show had not been finalized.