iPod fans have helped make Apple iTunes one of the top ten music sellers in the US.

New figures by NPD show that iTunes is outselling many popular ‘offline’ stores, reporting more music sales than both Tower Records and Borders.

The increasing success of digital music, combined with a retail slowdown, saw iTunes grow from the 14th biggest music seller to seventh in the three months leading up to September.

In more good news for Apple, NPD analysts predict that iTunes can expect to see its share of the market grow larger still.

The new figures are further confirmation that digital music is an increasingly important part of the music business and Apple iTunes is set to lead the trend, providing seven out of every ten songs downloaded.