NEW YORK (AP) _ Airline cabins are a bit closer to being just another office for business travelers.

On Thursday, American Airlines became the latest and biggest air carrier to announce it was changing the telephones aboard its planes from analog to digital technology.

That means voice calls will be clearer and passengers with computers will be able to send and receive faxes and communicate with computers at the office. Air-to-ground phoning represents a tiny fraction of all telecommunications but airlines are trying to keep up with the rapidly changing industry and court business travelers, who typically pay the highest fares. International flights may soon have phone systems that are connected by satellites.

''What we are attempting is to meet the customer's needs by presenting the office-in-the-sky concept,'' said Kathy Libonati, managing director of product design at Fort Worth, Texas-based American.

In time, phone calls from planes may become cheaper, she said. They now typically cost $2 per minute.

American chose Seattle-based Claircomm Communications, jointly owned by McCaw Cellular Communications Inc. and Hughes Network Systems, to equip its 650 planes with the new equipment. Alaska, Northwest and Southwest airlines have made similar deals with Claircomm for their smaller fleets.

USAir was the first to begin updating its fleet with digital telephones. Its phone provider, In-Flight Phone Corp., is also installing video screens on each seat that show connecting flight information, weather and news and even some live TV broadcasts. The work has been done on nine USAir 757s so far and is to be finished on the 412-jet fleet by the end of next year.

Typically, phone providers bear the costs of installing the systems and then share revenues from phone calls with the airlines.

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