OutKast have picked up a host of awards in the past year

The hip-hop duo received the accolade for selling at least 400,000 downloads of Hey Ya, while The Way You Move and Roses got platinum awards for 200,000.

Maroon 5, D12 and Hoobastank have also been given platinum awards.

The Recording Industry of America also named Beyonce and Usher gold winners for selling over 100,000 downloads.

The Recording Industry Association of America, which represents the major record companies, handed out 45 gold awards in all. The awards display a shiny abstract design over the recording's cover art.

Online market

Music downloads still represent a fraction of total sales for the recording industry, but they are growing rapidly.

Analysts expect the commercial online music market in the US to grow to about $1.7bn (�930m) in 2009 from $100m (�54m) last year.

For several years, music fans could only obtain music online through illegal file-sharing services as recording companies were slow to react to the internet.

Limited catalogues and restrictive terms of use affected early attempts to sell music online until Apple launched its iTunes service in spring last year.

Apple has sold more than 125 million songs at roughly $1 (54p) each through its US service, while competitors include Wal-Mart, Virgin and Microsoft.