Singapore Airlines Plans 52-Jet Purchase : Aviation: Boeing and Airbus would be main beneficiaries of $6 billion in orders. Other Southland firms would also benefit.

Singapore Airlines is prepared to buy up to 52 wide-body jetliners worth $6 billion from Boeing Co. and Airbus Industrie, an airline spokeswoman said Friday, in what would be another welcome boost for Southern California’s beleaguered aircraft industry.

The carrier’s order would particularly benefit Northrop Corp., which builds the fuselages for Boeing’s 747 jumbo jet in Hawthorne, and several dozen other 747 suppliers in the region.

Singapore Airlines, whose 63-plane fleet is already dominated by 44 747s, has invited proposals from manufacturers to supply additional 747s, along with A340s built by Airbus, the European aircraft consortium, airline spokeswoman Agnes Huff said in Los Angeles.

The A340 entered service a year ago, and Hong Kong-based Cathay Pacific Airways and Air Canada are among the carriers that have ordered the plane.

Huff said Singapore Airlines hopes to formally place its order within the next few months.

A third major manufacturer, McDonnell Douglas Corp.’s Douglas Aircraft unit in Long Beach, is also welcome to submit a proposal to Singapore, Huff said. But she said Boeing and Airbus were invited because those are the two makes of jets the airline flies.

The airline’s expected order follows the February announcement of a $6-billion order planned by Saudi Arabia’s national carrier, Saudia. Boeing and Douglas are negotiating with the Saudis about sharing that order.