Amazon has announced plans to sell music without digital rights management (DRM) on a global basis.

The company will carry tracks from the big four music companies and around 33,000 independent labels.

Bill Carr, Amazon's vice president of digital music, said that promising US sales had led the company to offer the same service worldwide.

"We have received thousands of emails from Amazon customers around the world asking us when we will make Amazon MP3 available outside the US," he said.

"We are excited to tell those customers today that Amazon MP3 is going international this year."

Amazon has built a following by selling music unencumbered with DRM controls, and which can be played on any music player.

Apple led the way in this area, after using its market clout to persuade the major record labels that DRM-free music was the way forward.

Amazon MP3 currently carries 3.3 million songs, at a cost of 89c to 99c per track and $5.99 to $9.99 per album.