In an unprecedented move, Warner Bros. has opted to sell the soundtrack to “Three Kings” exclusively online — through e-tailers CDNow and MP3.com — instead of through traditional retailers.

The decision marks the first time a studio has opted to go the e-tailing route with a soundtrack first.

The move, which begins Friday with the release of the pic, is actually a test run for Warners and Atlas Entertainment, who still retain the right to sell the soundtrack in brick and mortar stores should the online effort fail.

Two versions of the soundtrack will be available.

CDNow will offer a music-only version of the soundtrack (featuring Public Enemy, the Beach Boys and Rare Earth). CD will be sold for $11.99.

CDNow Inc. is merging with Columbia House, the jointly owned music club of Sony and Time Warner.

MP3.com will offer an audio-visual enhanced CD ($13.99) that includes two trailers and a clip of an interview with actor Ice Cube. The site will also exclusively offer a free MP3 download of “The Gold,” by “Kings” composer Carter Burwell. The site receives 400,000 hits per day to its library of 154,000 downloadable songs.

“We wanted to give each site something different,” Gary LeMel, prexy of music for Warner Bros. Pictures told Daily Variety. “MP3.com came to us with the idea. We wanted to work something out with our own online music retailer CDNow, as well.”

LeMel said the soundtrack may not hit traditional retailers for months, depending on how well the CDs sell online. If they do, Warners may go the same route with future soundtracks. “Three Kings” stars George Clooney, Mark Wahlberg, Ice Cube and Spike Jonze and helmed by David O. Russell. Warner Bros. and Village Roadshow are releasing the pic.