Gnarls Barkley went to number one with 31,000 download sales

The Official UK Charts Company plans to hold talks with music labels about the move after collecting sales data from retailers, reports Music Week magazine.

Apple says its online iTunes store has sold 35 million videos worldwide since they were introduced in October 2005.

Downloaded singles were included in the chart last year, and they can now be counted a week before shops get copies.

Music Week said that the latest move recognised "the explosion of the music video download market" led by iTunes and mobile network 3.

3 says its audio sales account for 3.7% of the singles chart.

Omar Maskatiya, director of the Official UK Charts Company, is quoted as saying: "It's up to us to start talking to the retailers and getting an idea of how many are selling from all the labels.

"Initial indications are really good and we hope that, by October, we will have enough data and analysis to take to the labels, which will then make a decision about when it's incorporated into the chart."

Crazy

In April 2005, downloaded singles where copies were also on sale in shops were incorporated into the singles chart.

New rules introduced this year allowed sales to be counted as long as physical copies went on sale a week later.

This development led to the first number one based on downloads alone, Crazy by Gnarls Barkley, in April.