United, whose request for federal loan guarantees was denied Wednesday, owes Boeing Capital Corp. $1.3 billion in financing for the purchase of about a dozen Boeing jets. The planes are mostly late-model 777s.

United is current on its payments to Boeing, said Boeing Capital Corp. spokesman Russ Young. Boeing declined to comment on when its next payment from United is due.

Boeing stock closed down 2.9 percent, or 97 cents, at $32.96 on the New York Stock Exchange Thursday. Stock trading in UAL, United's parent company, was halted after sliding 59 percent to $1.28 a share.

If United files for bankruptcy protection, the airline would have 60 days to meet the terms of its current financing agreement, negotiate a new one, or surrender the jets to Boeing, Young said.

United - which was spun off from Boeing in the 1930s - has been talking with Boeing about negotiating new financing terms and other alternatives, although no decisions have been made, Young said.

Since the Sept. 11 terrorist attacks, Boeing has slashed production rates, cut nearly 30,000 jobs, deferred deliveries of more than 500 jets and announced 5,000 more job reductions for 2003. It also is locked in a battle with rival Airbus of Toulouse, France, which has steadily been seizing market share and is poised to match Boeing in production of jets next year.

"To the extent that United is going to be shrinking its capacity, they will be ordering less planes and using less supplies and that can't be good for their supplier partners," said Jim Corridore, an airline equity analyst with Standard and Poor's.

Even if United defaults on its payments, Boeing is in a relatively good position, analysts said.

The company will likely be able to find other carriers wanting to pick up the popular 777s, said Peter Jacobs, an analyst with Seattle-based Ragen MacKenzie, even in the current economic downturn.

"The triple-sevens have pretty broad usage in the world's major airlines," Jacobs said. Of the approximately 1,700 excess planes currently parked, only about five are 777s. "Those aircraft can be placed relatively easily," he said.

Jacobs also noted that "United turned its back on Boeing several years ago," when it turned to Boeing rival Airbus to supply its narrow-bodied airplanes, and has only one order for a 777, for delivery in 2005.

It's too early to say how deeply Boeing could be affected, said Tassos Philippakos, senior vice president of Moody's Investment Service. The impact will depend on what routes United decides to cut and other management decisions, he said. "There are many questions that no one has an answer to right now."

He added that despite the $1.3 billion in financing, the actual risk is smaller because of the value of the collateral, the jets.

A United bankruptcy petition won't immediately affect Boeing's production of commercial jets, said Cai von Rumohr, analyst with SG Cowen.

But it could cause indirect effects. United would probably cut flights and park some of its 747, 767 and 757 jets, sales of which have been especially hurt by the downturn in the commercial aviation industry. Those aircraft production lines in Renton and Everett have already slowed considerably and Boeing has not been winning many new orders for the jets.

United's $1.3 billion in financing is the largest portion of Boeing Capital's total portfolio of $11.5 billion. In Boeing's third quarter, the company took a $250 million non-cash charge against earnings to, among other things, reflect United's deteriorating credit rating and to shore up its reserves in the event of a default.