Downloads on verge of outpacing CDs; downloads soon to be dominant singles format, as post-Xmas surge sees digital sales mushroom.(Charts)

The combined singles chart has moved into its second year of operation, with downloads now accounting for an average of around 50% of each track's weekly sales inside the Top 40.

Twelve months after the combined singles chart's launch, digital is on the verge of ousting CD as the leading format in the upper echelon of the countdown, as physical sales continue to fall away.

A fortnight ago, when the chart reached its first anniversary, digital's share of each track's total weekly sales averaged 49.7%, a sharp rise from the chart's birth in April 2005 when the figure was just 20.7%. In turn, downloads two weeks ago accounted for 42.4% of all Top 40 sales, compared to only 14.6% when the chart started.

Universal Music commercial director Brian Rose, whose company scored a top five debut two weeks ago with Rihanna's SOS almost solely on digital sales, says the growth of the market had been strong up until Christmas, but since then has been "incredible".

"It's a mixture of things," he says. "The market is starting to mature and everyone who has an MP3 player, rather than just using it to manage their existing music collections, are aware they can get the tracks they want digitally and the great news is they are doing it more often than not from legal services as opposed to illegal ones. There's also an increased awareness of and comfort in using the technology."

Across the entire singles market, digital predictably dominates, typically making up 75% of all sales, with physical only accounting for around a quarter of the sector. But it is in the Top 40 where growth has been particularly remarkahle, because high street sales continued to set the pace during the early weeks of the combined singles chart.

Digital's improving share of the Top 40 has been partially aided by the introduction in March of a rule allowing singles into the chart on download-only sales a week before an ...