NEW YORK (Reuters) -- Boeing Co. said Tuesday it will start production of two new long-range versions of its popular 777 wide-body jetliner, with the first delivery expected in September of 2003.

"We've got more than enough (customer) commitments to be absolutely certain we've got a winning program," Boeing Chairman and Chief Executive Phil Condit said at a joint news conference with top executives of General Electric Co.GE is the sole-source producer of engines for the new jets, the 777-200 and 777-300.

Boeing declined to identify any launch customers, but said Asian airlines are expected to be the biggest market.

Boeing has about 30 launch orders worth about $5.5 billion, according to a report in Monday's Wall Street Journal siting executives familiar with the matter. Launch customers include Japan Air Lines, Singapore Airlines , and Malaysia Airlines System, according to the report, which Boeing has not confirmed.

Assuming that 450-500 airplanes are delivered, "you're talking $15-20 billion (revenue) for GE over a 20-year period," said Jim McNerney, president of GE Aircraft Engines.

GE Aircraft Engines had 1999 revenues of $10.6 billion, up 3 percent over 1998.