Despite the current UK heatwave, two of the country's biggest radio groups predict a gloomy summer for advertising revenues.

GCap Media, the new radio titan formed by the recent merger of Capital Radio and GWR, and Chrysalis both saw ad revenues fall sharply in May.

GCap, which controls more than a third of the UK's commercial radio market, revealed a 14% drop compared with the same month last year. Chrysalis says its sales in the three months to May 31 fell by 14.5% versus last year.

David Mansfield, ceo of GCap, describes the UK advertising climate as "pretty grim" and offers little optimism for a speedy recovery. He says consumer spending is drying up and every media owner is experiencing the fall-out.

Chrysalis says: "The advertising market remains volatile and continues to be affected by the slowdown in consumer spending," adding that there is "little visibility" for July or August.

Analysts cut their forecasts for both the radio operators. GCap is now expected to make a full-year pre-tax profit of around £25 million ($45m; €37m), down 20% from previous forecasts. Chrysalis is tipped to make £1m, against an original forecast of £5.5m.

Data sourced from The Times Online (UK); additional content by WARC staff