American Airlines is negotiating with Airbus and Boeing over the purchase of at least 250 planes in a deal worth an estimated $15 billion, the Wall Street Journal reported Thursday. The deal, which the Journal said would replace 38 percent of American\'s current fleet, could threaten Boeing\'s longstanding hold on the US airline sector and allow Airbus to get a crucial foothold in the market. The Journal cited two people familiar with the talks as saying that American went to the European manufacturer first and hashed out a tentative deal several weeks ago without telling Boeing. It then brought the deal to the US manufacturer and asked for a counter offer, the sources told the newspaper. American is interested in Airbus\'s single-aisle family of A320 airplanes and a new A320 model that will take off in 2015, as well as Boeing\'s 737 family of airplanes, the Journal said. The newspaper said American hopes to conclude the order this summer. Earlier this month Airbus celebrated a $72 billion haul of orders in a home turf victory over Boeing at the Paris Air Show. The orders included the biggest single airliner deal in history, with Malaysia\'s AirAsia agreeing to buy 200 of Airbus\'s A320neo medium-haul jets for $18.2 billion (12.7 billion euros). Boeing has lagged behind its rival since the start of the year, with Airbus receiving at least 725 firm orders and Boeing just 195. The surprise key to Airbus\'s success has been the A320 an unglamorous single-aisle workhorse now available as the \"Neo\" or \"New Engine Option\", which the company says is 15 percent more fuel efficient.