Global Radio is expected to sell stations in the East and West Midlands, to avoid its purchase of GCap being referred to the Competition Commission.
While the Office of Fair Trading has cleared Global to operate all stations in London that would be owned following the sale, the overlap of GCap's services in the Midlands would mean a lack of choice for advertisers and audiences.
Global Radio has submitted plans to dispose of several stations from either the Global or GCap portfolios; the exact details of which stations are to be sold are being kept confidential until a public consultation is undertaken.
Simon Pritchard, the Office of Fair Trading's senior director of mergers said: 'Merger efficiencies benefit customers and put pressure on rivals. In this case, they tipped the balance in favour of clearance in London. This shows that with the right facts, efficiencies can make a difference, even at first phase, and even in a horizontal merger with high market shares.
"The divestment remedies [proposed by Global Radio] in the Midlands, where efficiencies were not sufficient, are about restoring competition to make sure customers will not be harmed."
In the West Midlands, Global's Heart and Galaxy stations compete closely with BRMB, Wyvern, Beacon and Mercia, while in the East Midlands Heart competes with Leicester Sound, Trent and RAM.