Jim Whitehurst, the Chief Operating Officer of Delta Air Lines, Inc., who played a key role in Delta's restructuring, has announced his immediate resignation. Many analysts think he left because he was snubbed by Delta's board when it chose the company's next chief executive to replace Gerald Grinstein when he retires Sept. 1.

Although Whitehurst was seen as an almost certain choice, Delta's board went outside management ranks to choose the ex-head of Northwest Airlines Corp., Richard Anderson. Jim Whitehurst, an MBA from Harvard Business School, was tapped in 2002 by Chief Executive Officer Gerald Grinstein to lead the historic traditional airline out of bankruptcy and he is believed to have done quite well.

"After careful thought, I have decided it is time for me to move on to the next chapter of my career," Whitehurst said in a memo to Delta employees obtained by Reuters news agency. "The people of Delta are an amazing, innovative and dedicated group of professionals, and it has been an honor to serve you and this great company," he said.

"We respect his decision to move on in pursuit of new challenges," said CEO Grinstein in an official statement.

Jim Whitehurst, 39, is to receive more than $1 million which includes his annual base salary of $382,500 plus 100% of his target annual incentive amount. He will be prohibited from working for a competitor, Delta said, but the airline didn't specify how long that agreement lasts.

Delta Air Lines, Inc. entered Chapter 11 on Sept. 14, 2005, and emerged on April 30 2007, surviving a hostile takeover bid by Tempe, Ariz.-based US Airways Group Inc. The airline company's flights land in over 332 destinations in 57 countries across 5 continents. Delta is the second-largest airline in the world in terms of passengers carried and the nation's no. 3 carrier.