One of the leading figures of the Edinburgh Festival Fringe has warned against four of its main venues breaking away from the rest of the annual festival.

Four key venues - the Assembly Theatre, Underbelly, Gilded Balloon and Pleasance - recently revealed plans to promote their own Edinburgh Comedy Festival from this year with their own sponsor, drawing claims they are trying to break away from the traditional Fringe.

Nica Burns, a theatre producer who for years has run the premiere comedy award of the Fringe, formerly the Perrier Award and now called the if.comedy awards, said: "Any proper breakaway would not be a good development in my view.

"I would be very sorry if every comedy show at the Fringe was not in the main programme in the future. It would not be good for the public and not be good for the comedy shows themselves.

"If this is just a way of marketing for the four venues, then fine, but if it turns into more than that, then that would be a great shame in the context of the Fringe as a whole. Right now I would say: Don't split up something that has been created by artists over many years, working together'."

Meanwhile, the Edinburgh International Festival last night said it had sold £1m tickets already this year, a record, including takings of £250,000 in one day.

The hottest tickets were for Giselle, Matthew Bourne's Dorian Gray, the Gothenburg Symphony Orchestra and the festival's opening concert.