Sony has announced it will launch a new online music store this spring, which will, among other things, allow United Mileage Plus members to spend their miles for music downloads.

In an era when the recording industry is at odds with online file-sharing “pirates” like Kazaa.com, the promotion will be one way in which a lawful file-swapping service — in this case, Sony Connect — can compete.

“What Connect has finally done is beat the pirates at their own game to offer better-quality files without consumers having to spend a dime,” said Jay Samit, Sony Connect’s general manager.

The promotion will allow members of Mileage Plus to exchange their miles for tracks through a co-branded Sony-Mileage Plus Web site. Sony and United sources said the number of miles needed to download a song had yet to be determined.

“Obviously, the whole digital media revolution is extremely exciting for us. To bring this to the Mileage Plus membership is a real value,” said Dave Keenan, United Airlines’ vice president of loyalty services. “Sony is the market leader in consumer electronics and in music and at the end of the day they’re going to be the winner.”

In a related topic on the popular flyertalk.com Web site, members of various frequent flyer programs have voiced opinions that downloads should cost no more than 50 miles per song.