The spokesman said the CAA knew many airlines had expressed interest in offering such services but added: 'None have formally approached us yet.'

'It's down to the airlines to decide whether they want to fit the systems then they would have to get approval for that,' he said.

The plan is to install small mobile phone base stations, called pico cells, in aircraft that will be switched on after take-off. The base station generates a bubble of coverage in and around the aircraft.

Calls made via the pico cell will be routed to terrestrial networks via satellite link. Across Europe radio spectrum has been set aside for the technology.

The services could stop working once aircraft leave European airspace.

Initially, only second generation networks will be offered but growing interest would mean that third generation, or 3G, services would follow later, said Ofcom.

The cost of making a mobile phone call from a plane will be higher than making one from the ground.

In the UK, regulator Ofcom said it would investigate and address any evidence of 'excessive charges and abuses of competition' if prices were set unfairly by airlines and mobile networks.

Mobile use is currently prohibited on planes because there is evidence that they interfere with onboard communication and navigation systems.

Research published in 2003 by the CAA found mobile phone signals skewed navigation bearing displays by up to five degrees.

There are also fears that mobiles used onboard aircraft that are not fitted with pico cells could disrupt the working of terrestrial networks.

For details - http://news.bbc.co.uk/2/hi/technology/7314362.stm#system