"One of the beauties of our business model is we don't have to own a single satellite," said Connexion spokesman Sean Griffin.
Through the deal, Connexion will have access to AT&T's network of satellites and ground connections above US territories and waters, allowing Boeing to link its planes to the Internet.
Connexion handles all the servers and processing on board aircraft to deliver Internet and entertainment to displays at each seat.
While German airline Deutsche Lufthansa and British Airways have committed to using the service on limited routes from Europe to the USA, Connexion lost its three major backers, American Airlines, Delta Air Lines and United Air Lines, last year.
This week, British Airways announced that it plans to begin a three-month trial of Boeing's Connexion service beginning next February. The service will be installed in the airline's First, Club World and World Traveller Plus cabins.
Connexion by Boeing is a division of Boeing in Chicago, USA.