GCap Media, the UK's biggest commercial broadcaster, has seen its shares sink 13% after it blamed a tough advertising market for a drop in annual profits.
Capital, Planet Rock and Classic Gold are among GCap's stations
Profits at the Classic FM owner fell 35% to £14.4m in the year to 31 March, with revenues down 9% to £200.1m.
GCap added it had been hit by a drop in the number of adverts it plays on Capital and a loss in revenues after the sale of two Century stations.
In a bid to halt the decline, GCap said it was aiming to cut costs by £5.5m.
The "operational efficiencies" will be made over the current year.
GCap's shares fell after the results were released and closed down 14% at 222.5 pence in London.
The results came just hours after the group's commercial director, Duncan George, announced he was quitting the group.
Mr George was in charge of integrating the sales and commercial operations of GWR and Capital when the companies merged in 2005 to form GCap.
Since then, the firm has suffered a drop in revenues and audience numbers. Mr George will leave the company next week.
Last year, the company blamed difficulties at its Capital Radio station and merger costs for a sharp drop in annual profits to £22.2m from £37.3m in 2005.
Many media firms have complained that competition from online adverts has eaten into their markets, with GCap itself blaming the "proliferation" of alternative media options for a slide in advertising.
It explained that across its stations, advertising revenues from all sectors - except the business and industrial category - had fallen.
As a result 84% of its revenues were generated from radio adverts over the year, compared with 86% in 2005/6.
Despite its problems, the company said it had made progress over the past year.
"The market remains difficult to predict, but we have seen an improving trend in advertising revenue performance, and we outperformed the market in the last quarter of the financial year," said chief executive Ralph Bernard.
GCap added its audience numbers had stabilised, it had taken full control of the Planet Rock and Classic Gold stations as well as launching new station The Jazz.