The Texas company, EDS, is to acquire the information technology unit of the collapsed Swissair Group, Atraxis.
The Swissair Group formally approved the takeover and it was signed by both parties on Monday, a statement said without giving financial details.
Final approval is needed from antitrust authorities before the deal can be completed.
EDS is to handle flight reservations, airport management and information services for Atraxis customers, the company said.
Atraxis boss Armin Meier told Swiss television that EDS - the world leader in information technology for the airline industry - would retain the majority of employees.
Atraxis is one of three subsidiaries of the Swissair Group facing a cash crunch following the collapse of Swissair last month. It was saved from immediate collapse by a $62.5 million bridge loan last week.
Refused to pay more
The Swiss government and private business put up SFr4.24 billion ($2.65 billion) to rescue Swissair, but refused to stump up more money for the subsidiaries, even though they are vital to the continued operation of Swissair, and its successor.
The other firms - ground handling company Swissport and maintenance company SR Technics - are also expected to be sold.
Atraxis, based in Zurich, employs 2,100 people and has contracts with more than 60 airlines and around 40 airports. The statement said the deal would give a European base to EDS.
Regional airline Crossair took over many of the Swissair services on October 28 after the announcement of the rescue package.
Swissair's intercontinental flights are continuing on a limited schedule and should be incorporated into Crossair next year.
Swissair was already suffering from a failed expansion strategy that led to a loss of SFr2.9 billion in 2000 even before the September 11 terrorist attacks in the US hammered the airline industry.
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