The airport group led by Manchester City Council has stepped up pressure on the Spanish owner of London's Gatwick Airport. Manchester Airport Group has urged the Competition Commission to appoint an independent trustee to oversee any sale by BAA, which is owned by Spanish firm, Ferrovial. The group (MAG), which is owned by a consortium of local authorities, is currently heading the race to buy Gatwick, which has been put up for sale by Ferrovial after the commission ruled it controlled too many of Britain's runways. It has asked the commission to bring in a trustee to oversee the process, to ensure a fair sale. The group argued Ferrovial could sell it to a private equity fund rather than a rival, in order to protect its remaining interests. The Terra Firma private equity firm is known to have confirmed its interest in bidding, as has Virgin Atlantic boss, Sir Richard Branson, who is looking to expand his airline's UK presence. MAG has added to pressure on Ferrovial by expressing interest in creating a consortium with Scottish councils to buy Glasgow Airport, which BAA has also been ordered to sell. A MAG spokesman said: ‘We have consistently stated that the group is interested in acquiring assets which will add value for shareholders, and this could include one or more of the BAA airports.' BAA hit back with a warning that a trustee could put off potential bidders at a time when global financiers were nervous. A BAA spokesman said: ‘Ultimately, we expect the market will determine who buys the airport, and we will not provide a running commentary on the views of individual bidders as they put forward their case.'