Plans were unveiled today to extend mobile phone coverage to all 275 London Underground (LU) stations by 2008.

Over 70 firms have formally registered interest in providing the mobile services, and a trial scheme is promised at one station by 2006.

"We have received an excellent initial response from the market, which has demonstrated considerable interest in providing mobile phone services and other exciting technologies for LU customers," said Richard Parry, LU director of strategy and service development.

"We intend to issue a consultation document for those which have expressed interest so that we can get further information from the market about how we could best provide these services."

According to LU, mobile phone companies are not the only parties interested in supplying the technology. DAB digital radio and Wi-Fi companies are also pitching for the contract.

LU is currently assessing different technologies and is expected announce the successful supplier by 2007, allowing some stations to be connected by the summer of 2008.

The plans do not yet include coverage inside tunnels.