Global online sales of digital music nearly doubled to $2bn in 2006 but that growth will slow this year, according to new research from the London-based International Federation of the Phonographic Industry (IFPI).

The IFPI said those sales now made up 10% of music sales across all formats but that the growth had not yet reached a significant enough number to offset the decline in sales of physical formats like CD – the so-called ‘holy grail’.

IFPI chief executive John Kennedy said the grail had almost been reached in the US, the UK and Japan, but he did not think digital sales would double again in 2007.

The organisation’s 2007 Digital Music Report showed how net users last year made 795m legal track downloads, a rise of 89% on 2005.