'Speed of Sound' issued April 19 as download only.

Coldplay's single "Speed of Sound" reached No. 1 on all 15 iTunes Music Stores worldwide only one day after its April 19 release.

EMI Music U.K. & Ireland says the single is "on course to register the highest week-one download sales for any new track."

The song topped iTunes Music Stores in Austria, Belgium, Canada, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, the United Kingdom and the United States.

Apple did not discluse figures on the number of downloads sold.

In the U.K., the single premiered April 18 on national top 40 station BBC Radio 1 during DJ Steve Lamacq's evening show. It was released digitally by Parlophone through coldplay.com and through all legitimate digital retailers at midnight. It will be available physically May 23.

"Fans want to be able to buy the music they hear on the radio instantly, and the beauty of digital is that we can now deliver that," said EMI Music U.K. & Ireland chairman/CEO Tony Wadsworth in a statement.

"Speed of Sound" is the first single from the band's third album, "X&Y" (Parlophone), due out June 6 worldwide and the next day in the United States.

Wadsworth tells Billboard.biz he anticipates the track to be No. 1 on the British download chart for the week ending April 23. However, it will not qualify for the official new singles chart; only tracks available both physically and online qualify.

"It is unfortunate that the rules are such that it does not qualify for the combined chart," says Wadsworth.

On April 19, the band performed a secret gig in London to a select audience of 500. The show is due to air May 30 on all MTV channels.

Coldplay will headline the first day of the Coachella Music Festival on April 30 in Indio, Calif.