Bell Atlantic will own 55 per cent of the new company, which will serve 20 million customers, and Britain's Vodafone, the world's biggest cellphone operator, will own the rest.

The network that Vodafone inherited in its $62 billion takeover in January of San Francisco's Airtouch covers most of the western states, while Bell's covers most of the east.

The tie-up is the fast track both of them sought towards a ready-made coast-to-coast network, better able to compete with existing Pan-US Wireless companies such as AT&T, Sprint PCS Group and Nextel Communications Inc. "This is a logical fit, naturally uniting our US properties and strong management teams and enhancing the benefits of Bell Atlantic's merger with GTE," Bell chairman and chief executive Ivan Seidenberg said.

The deal isexpected to take six to 12 months to complete. Vodafone shares gave a muted initial response, gaining 2 per cent or 26 pence to 13.29 pounds shortly after the statement. "Much has already been discounted," said SG Securities Telecoms analyst Sean Johnstone in London.

"This deal has been on the cards for a while." Bell estimated revenue enhancements, cost savings and capital efficiencies had a net value of some $7.4 billion. The new business will initially assume or incur up to $10 billion in existing and new debt. Vodafone AirTouch's recourse debt is expected to decline by $4.5 billion.

The new business will be managed by Bell and based alongside it in New York. It will cover more than 90 per cent of the population and 49 of the top 50 state wireless markets.

Included in the new venture will be the wireless assets of Texas-based GTE Corp, whose merger with Bell is expected to be completed by the first quarter of 2000.