UPDATE:Delta Gives Pilots 'Weeks' To Ink Deal,Avoid Ch 11 Monday October 4, 3:48 PM EDT ATLANTA (Dow Jones)--Delta Air Lines Inc. (DAL) head of operations Joe Kolshak said pilots only have a few weeks to agree to cheaper contracts and avert bankruptcy, but conceded that still might not be enough. In a speech to the Society of American Business Editors and Writers here Monday, Kolshak said pilot costs are his "single biggest concern," and every day without a new contract make it more difficult for the Atlanta carrier to remain out of bankruptcy. "If these elements aren't in place in a matter of weeks, our airline will have to restructure under Chapter 11," Kolshak said. He added: "There are no guarantees that will avoid bankruptcy" but "it will go a long way." The airline seeks to cut annual pilot costs by $1 billion as part of a $5 billion cost-cutting plan. Already Delta has cut $2.3 billion in annual costs, and last week announced a plan to cut another $1 billion by trimming the salaries and benefits of other employees. Even if the pilots agree to $1 billion in cuts and they've only offered $750 million so far that leaves another $ 700 million in cuts that Delta hasn't yet outlined. Along with salary cuts, Delta has asked pilots to freeze their defined benefit pension plan, and to consider moving to a defined contribution plan, Kolshak said. Joe Leonard, chief executive of rival Atlanta airline AirTran Holdings Corp. ( AAI), said he has doubts Delta can pull it off outside of Chapter 11, though he hopes Delta tries. "I would prefer to see Delta work out something with the pilots. If pilots agree to what Delta wants, Delta won't have nearly enough to get themselves well," Leonard said in a speech at the same conference Monday. Further, Leonard said, filing for bankruptcy to fix the airline puts Delta at an unfair advantage. "They end up not having to pay a lot of their bills....There's something morally wrong with that," he said. "It gives a disadvantage to people like us who pay our bills." If Delta files for bankruptcy, that would mean 42% of the U.S. airline capacity would fly under Chapter 11, with UAL Corp. (UALAQ) and US Airways Group Inc. (UAIRQ) in the same boat. Delta's Kolshak said that while some airlines may abuse bankruptcy, Delta views Chapter 11 as a last resort. Delta's plan to save the airline also involves rearranging half of its network in order to make operations in Atlanta more efficient. By trimming the amount of time airplanes remain on the ground, Delta aims to squeeze 13% more flying out of the Atlanta operations, without adding more gates. Meanwhile, the airline is cutting its operations in Dallas down from hub status, and reallocating those jets, many to Atlanta. Kolshak said changes along those lines would take place in or out of bankruptcy. AirTran's Leonard said changes in Atlanta operations are misguided. "I think moving more capacity to Atlanta is a big mistake," Leonard said, because Delta already dominates many routes out of Atlanta, so there's little strategic or profit gain to pouring more resources on them. Roger EWROPS