BT and AT&T are working together to develop a global mobile telephone network, they say.

A $10bn global fixed-line venture between the two companies is already at an advanced stage, having been cleared by the European Commission.

That deal will see BT and AT&T integrating much of their international activities in a joint venture to provide the communications needs of multi-national companies and internet service providers.

Global competition

They said their new mobile operation would be able to offer network access to customers in 150 countries.

AT&T president John Zeglis said: "If you travel, you expect your digital phone to work anywhere and everywhere with all of the advanced features you have - just as if you were at home.

"This is not possible in many cases today for a whole host of reasons, including incompatible technology and government regulation.

"By pairing two of the leading telecommunications companies in the world, we think we can make some things happen that will eventually give customers those 'anytime, anywhere' capabilities from their mobile phones."

Shares up

The move comes as Anglo-American telecoms company Vodafone AirTouch discusses a tie-up with Bell Atlantic in a bid to increase its global coverage.

Deutsche Telekom has already said it plans to launch a global phone operation, having built up interests in the UK, the US, Austria, Poland, the Czech Republic, Russia and Ukraine.