NEW YORK — Nearly half of the short films being screened at this month's Sundance Film Festival will be available for purchase at Apple's iTunes store under a deal announced last week.

The digital downloads will supplement the free streaming at Sundance's Web site, which will offer the shorts for only a three-month period beginning today, the start of the festival in Park City. The iTunes downloads are expected to be available for three years and, once purchased, will play for at least the life of the owner's computer.

"Streaming on our site is not the same as owning, and there seems to be a world out there for both," said John Cooper, the Sundance Institute's director of programming.

Filmmakers will get the bulk of the $1.99 download price, with Apple, the Sundance Institute and cable television's Sundance Channel sharing the remainder. Filmmakers also will be free to make deals with other distributors, including the Sundance Channel.

As of Thursday, at least 33 of the 71 narrative, documentary and animation shorts were slated to be distributed through the Sundance site and iTunes, Cooper said. He said a few more will be shown on the Web site only.

Like songs, television shows and movies bought through iTunes, the Sundance shorts will play on Macintosh and Windows computers with Apple Inc.'s free iTunes software as well as Apple's video iPods. Sales were to begin Jan. 22.

Cooper acknowledged that Sundance films tend to draw niche audience, but he expects demand to be sizable, given the millions who came online to watch Sundance shorts in past years.

There are no current plans to make full-length festival movies available online.

"What Sundance is really known for is as a platform for people to sell their films, and that's mainly the feature film," he said. "We didn't want to really interfere with that yet."