CHICAGO (AP) _ United Airlines chief executive James Goodwin has resigned, just two weeks after a letter he wrote was made public in which he predicted the troubled airline could perish unless its fortunes were reversed.

The company announced his resignation Sunday.

Two unions representing United employees called for Goodwin's resignation and the company's stock fell more than 20 percent last week in the fallout from the letter. Goodwin had said the airline was hemorrhaging cash following the Sept. 11 terrorist attacks.

In a statement released Sunday, Goodwin said he was ``proud to have contributed to the tremendous growth of United during my 34 years.'' He called said ``United is a great company and it is the right time for a new leader to guide the organization through the challenges that lie ahead.''

United parent UAL Corp. is expected to post operating of losses of $500 million to $600 million for the third quarter when it reports its results this Thursday. UAL stock hit a 14-year low Friday, falling 32 cents to close at $13.93 on the New York Stock Exchange.

United said Sunday that John W. Creighton was elected to replace Goodwin by a unanimous vote of the company's board of directors. Creighton has been a member of UAL's board of directors since 1998. Earlier, he served as president and chief executive officer of Weyerhaeuser Co., a forest products producer, from 1991 through 1997.

``Our immediate goal is to restore United's financial stability,'' he said in a statement. ``We intend to work hand-in-hand with our employees and unions to accomplish this task. ... Of course, our core business and getting our customers where they need to go safely and reliably will be my chief priority.''