PC game downloads are outstripping shop purchases in the US for the first time, suggest new figures.

According to data from market research specialist NPD Group, 11.2 million PC games were bought online, compared to 8.2 million physical unit sales, during the first 6 months of 2010.

NPD also said that PC sales in shops made up 57 per cent of all cash spent on PC games compared to 43 per cent for downloads, as a result of the higher average price of games sold in shops.

NPD's data also shows that the total sales of downloads and in-store sales dropped by 21 per cent, compared to the same period for the previous year.

Top of the download site list was Steamgames which is owned by Half-life creator, Valve.