NEW YORK — Junior Mints, Yoo-hoo, Drake's Coffee Cakes, puffy shirts: These are all things Jerry Seinfeld has endorsed — at least in his alter ego on his classic sitcom. Now, add Microsoft software.

Seinfeld will be a key pitchman in a planned $300 million fall advertising campaign for the software giant.

The Wall Street Journal first reported the plans. Citing people close to the situation, it reported the comedian will be paid $10 million for appearing in ads with Microsoft Chairman Bill Gates.

It's Microsoft's latest move to try to capture some of the cool quotient that rival Apple has appeared to win so effortlessly. But can Seinfeld turn the image tide for Microsoft?

"Seinfeld does represent sort of a challenge," said Brian Steinberg, television editor for the weekly advertising magazine Ad Age. "He's not Dane Cook. He's got a more sophisticated everyday take on things. He often comes across as a questioner of conventional wisdom but also can be kind of a crank. It's a fine line to walk when you're dealing with a younger person."

Steinberg did point out that the firm producing the spots — Crispin Porter and Bogusky — is known for creating commercials that appeal to young males, particularly in its campaigns for Burger King.

Seinfeld has shown himself to be a superior promoter in the past, particularly for American Express and in selling his Dreamworks animated film "Bee Movie" last summer.

For "Bee Movie," which Seinfeld co-wrote, co-produced and voiced, he also created 20 "TV juniors," which seemed less like commercials than one-minute bite-sized bits of comedy. The promotion of the film began with him dressing up as a giant bee at the Cannes Film Festival.

"You gotta sell it," Seinfeld said last year. "I've never been uncomfortable with that aspect. I don't feel like it's beneath me to sell what I did."

But Seinfeld's greatest triumph — the nine seasons of "Seinfeld" — ended more than 10 years ago, which means that many young computer users were still watching cartoons during his pop culture dominance.

Of course, the show is still on nightly reruns and Seinfeld has been active on the standup circuit. There have even been efforts to bring "Seinfeld" to younger demographics. Sony Pictures Television, which distributes "Seinfeld" in U.S. syndication, is holding a 26-city promotion in a cross-country bus tour of colleges.

Calls to Seinfeld's agent and manager went unreturned Thursday.

Vista, Microsoft's latest operating system that launched with the slogan "The Wow starts now," has received mostly negative publicity since its release last year. But sales are strong, since more than 90 percent of PCs sold worldwide run Windows.

Apple's ad campaign "Get a Mac" pits a coat-and-tie clad older guy (John Hodgman) representing a PC, against jeans and T-shirt-wearing Justin Long, who plays the Mac. The commercials have also poked fun at Vista.

Steinberg said this latest campaign by Microsoft shows that the rivalry between the software company and Apple is reaching the intensity of Coke and Pepsi's cola wars of years ago.

It's also possible Seinfeld seems more like a Mac guy, Steinberg said.

After all, it's a Macintosh that's seen in the background of his apartment on "Seinfeld."