The Official Charts Company (OCC) has confirmed that download sales have hit 500 million in the U.K.

The half a billion total was achieved at the end of August and took just over six years. The OCC says the download market took off in 2004; a download chart was launched in the same year.

A new record of 170 million download sales is forecast for 2010. The OCC said 102.3 million downloads were sold this year to the end of August.

"This milestone underlines how artists, labels and retailers in the U.K. have worked together to make Britain one of the world's most vibrant digital music markets," said Geoff Taylor, chief executive of labels trade body the BPI, in a statement.

"There are nearly 70 legal music services, more than any other country, and consumers continue to embrace the choice, value and innovation on offer. 500 million downloads is an astonishing achievement especially given the ongoing backdrop of widespread illegal downloading the music industry still faces."

The OCC also gave a presentation at the Entertainment Retailers' Assn. (ERA) annual general meeting in London today (Sept. 16). ERA and the BPI each has a 50% stake in the OCC.

OCC sales figures (to the end of August) showed album sales down 3.3% to 64.4 million, for a value of £436.2 million ($681.1 million), a decrease of 9.6% on the same period last year.

Cheaper digital bundles partly explain the album revenue decline: digital album sales are up 36% on the same period last year to 10.2 million units.

Florence and the Machine's "Lungs" (Island/Universal) is the biggest digital album up to the end of August with digital sales of 126,000, according to the OCC.

Lady Gaga's "The Fame" is the biggest selling album overall for 2010. It had moved 851,000 up to the end of August. The rest of the top five is also dominated by 2009 releases - from Alicia Keys, Florence and the Machine and Paolo Nutini - but Eminem has the fifth biggest seller with Recovery (Interscope/Universal) based on 10 weeks sales totaling 533,000 (and now likely to be around 600,000).

Owl City's "Fireflies" (Island/Universal) is the biggest single of the year, with 637,000 units sold - all of them digital.

Compilations account for 19.6% of the album market for the year to the end of August, a significant drop to go under the 20% share. The compilations sector has struggled following the demise of the Woolworths retail chain in the U.K. in early 2009.