In a statement the commission said Swindon-based GWR should be forced to reduce its holding in the station.

The inquiry into the complicated swap deal, which saw London station LBC fall into the hands of Chrysalis, said the merger may "reduce actual and potential competition".

Now the company must reduce its stake in Galaxy - now named Vibe - to 24.9% or below, and have "no material influence" over the station's output.

Currently GWR has a 49% stake, while Scottish Radio Holdings has a 51% interest.

In Bristol, GWR own the city's local radio licence, part-own Vibe, and run the area's digital radio service.

Advertising costs

The commission added that advertising sales for the station, should not be handled by Opus, which is owned by GWR.

The commission's statement went on to say that the merger may lead to higher advertising costs in Bristol, Bath, Taunton and Yeovil.

Competition Minister Melanie Johnson directed the Office of Fair Trading to "remedy the adverse competitive effects of the merger".

GWR said it would consider the findings of the inquiry and consult with its partners.