Seattle (WA) – Sony BMG will be joining Amazon MP3 as the last of the four major music labels to offer music download without copy protection.

The news from Amazon and Sony BMG follows on the heels of an announcement from December 27 that Warner Music Group would offer DRM-free music through Amazon’s digital music store. Universal Music Group and EMI had previously made similar announcement.

When Sony BMG’s music catalog is added at the end of this month, Amazon MP3 is expected to be offering more than 3.1 million different DRM-free music tracks from the four major music labels as well as more than 33,000 independent publishers. According to Amazon, MP3 music downloaded from the firm’s store can be played on “virtually any digital music-capable device, including PCs, Macs, iPods, Zunes, Zens, iPhones, RAZRs and BlackBerrys”.

"We are excited to offer Amazon MP3 customers DRM-free MP3s from Sony BMG, which represents many of the most popular musicians from the past and present," said Bill Carr, Amazon.com vice president for digital music, in a prepared statement. "Our Amazon MP3 customers will be able to choose from a full selection of DRM-free music downloads from all four major labels […] and over 33,000 independents that they can play on virtually any music-capable device."

Amazon launched its music store in September 2007.