UPDATE 1-Qatar to make Airbus order at UK air show

(Adds background on Qatar purchases)

NEW YORK, July 9 (Reuters) - Qatar Airways plans to hold a joint press conference with EADS (EAD.PA) unit Airbus next week at Britain's Farnborough International Airshow, likely signaling a major airplane order.

The company did not indicate what the press conference concerned, but an industry source said the Gulf-based airline was expected to announce a large plane order at the show.

Airbus, which competes with Boeing Co (BA.N) in the global airliner market, was not immediately available to comment.

Qatar Airways, one of the leading plane-buyers among quickly expanding Middle Eastern carriers, has traditionally been a staunch Boeing customer. Last year it ordered 30 of Boeing's new 787 Dreamliners and has 27 of its larger 777s on order.

At last year's Paris air show, Qatar confirmed a previously announced order for 80 new Airbus A350 XWB models -- which will compete with the 787 -- and three additional A380 superjumbos, worth about $17 billion in total. (Reporting by Bill Rigby; Editing by Lisa Von Ahn)