Apple leads the market with almost a 46 per cent share.
Mobile ad network InMobi experienced a 12 per cent rise in Q1 2012 on Q4 2011, as impressions hit 9.5 billion, while the mobile web holds a 78 per cent share of total ad impressions, up 20 per cent.
iOS fell by 2.7 per cent but continued to drive the market with a 45.7 per cent share, while Android rose to hit a 26.1 per cent share as RIM secured 16.7 per cent.
Lee Blyth, head of UK sales, InMobi, said: "In the UK, mobile ad growth continues to be driven by smartphones, and we have seen a 12 per cent increase in smartphone usage since Q4 2011.
"As 20 per cent more consumers use their mobile devices to access the mobile web, smartphone impressions now outnumber advanced phone impressions by more than 20 to 1, allowing more opportunities for premium publishers to create more engaging, interactive rich media ads."