According to a report from the British trade group The International Federation of Phonographic Industry (IFPI), the number of songs available for legal download doubled last year to over two million, with 165,000 albums available. MarketWatch reported the news, noting that online music sales now account for around 6% of record company revenues.

The IFPI's report, which is available from its Web site, notes that record companies earned US$1.1 billion from digital downloads in 2005, a three-fold increase over 2004's $380 million. Around 60% of that was online music, such as iTunes Music Store purchases, with the rest coming from cell phone sales.

In addition, single track downloads added up to 420 million worldwide last year, with subscription services adding 1.3 million users, for a total of 2.8 million now. Two years ago, 50 services offered legal online music and now 335 do, with 20 of them operating in at least three countries.

Looking just a the U.S., single track downloads more than doubled to 353 million in 2005, with a weekly average of seven million songs. Album downloads were 16 million, or 2.6% of the album market, which was up from 1% in 2004.

Peer-to-peer file sharing was the biggest threat to services such as iTunes, while cell phone downloads pose the biggest challenge in the future. IFPI's report noted that "dozens of 3G music services were launched" in 2005, while the first legal peer-to-peer service, iMesh, is in its Beta phase, with a full launch expected this year.