Sales of music via the Internet and mobile phones continued to boom in 2005, the recording industry reported Thursday, reaching 6 percent of global record company revenues.

The International Federation of the Phonographic Industry, or IFPI, also called on internet service providers, or ISPs, to join the fight against music piracy, which it claims severely erodes the profits of its 1,450 member record companies across the globe.

The London-based IFPI said that record company revenues reached $1.1 billion in 2005, up from $380 million in 2004.

Music fans around the globe downloaded 420 million single tracks in 2005, more than double the 156 million downloaded the previous year.

"2005 was the year that the digital music market took shape," said IFPI Chairman John Kennedy.

The IFPI added that the legitimate music business was gradually gaining ground on digital piracy. It said research showed that in Europe's two biggest digital markets — Britain and Germany — more music fans are now legally downloading music than illegally file-swapping.

A series of lawsuits against piracy by the IFPI have so far largely targeted individual song swappers for breach of copyright rather than ISPs which can claim that they have no knowledge of any piracy occurring on their networks.

Kennedy, who said he approached prominent ISPs a year ago about a coordinated response and has received "effectively a zero response," put them on notice Thursday that the IFPI would consider litigation if they did not join the fight against piracy.