By LEIGH STROPE WASHINGTON (AP) - As the clock winds down to Wednesday's strike deadline, United Airlines and its mechanics remain hopeful their dispute can be resolved without government interference. "We're determined to reach a new agreement, to avoid any disruption of service," said United spokesman Joe Hopkins. Negotiations have continued in the Chicago area since Friday, three days after the union rejected a contract proposal from the nation's second-largest carrier that would have given senior mechanics a 37 percent pay raise. Union members voted overwhelmingly to strike. Unless an agreement is reached, a strike is scheduled to begin at 12:01 a.m. EST Wednesday. President Bush, who will be in Asia until Friday, could ask Congress to intervene, but Congress has never stepped in to prevent an airline strike and isn't even in session this week. "That creates an atmosphere with the potential for settlement," said Frank Larkin, spokesman for the International Association of Machinists and Aerospace Workers. The sides aren't too far apart. The mechanics, who haven't received a raise since 1994, are unhappy about a provision that would let United cut their wages if other unions agreed to concessions to help keep the financially struggling airline aloft. They also oppose a plan that would delay retroactive pay until next year. United, based in Elk Grove Village, Ill., had been losing $10 million a day after the terrorist attacks and says it needs substantial wage givebacks as part of its financial recovery plan. Analysts played down the possibility of a walkout. "It would be mutually assured destruction of the airline as we know it," said Aaron Gellman, director of Northwestern University's Transportation Center. "I think there will be some sort of settlement that postpones the day when some of the more critical issues are addressed." Also complicating negotiations is a challenge to the union by the rival Aircraft Mechanics Fraternal Association, which is seeking to represent United's mechanics. Should a strike occur, Congress could act when it reconvenes the following week. It could extend the cooling-off period, impose a settlement or convene another emergency board to recommend a settlement. An emergency board called by Bush had recommended the contract that was voted down, but the union wasn't completely unhappy with that proposal. "As we have said from the outset, the (board's) recommendations should serve as a basis for settlement," said Robert Roach Jr., the union's general vice president. Airline strikes have become rarer. The last one was in spring 2001, when pilots at regional carrier Comair walked out for 81 days. Pilots at Northwest Airlines went on strike for 15 days in 1998. -- On the Net: International Association of Machinists and Aerospace Workers: http://www.iamaw.org/ United Airlines: http://www.ual.com/