Shares of American Airlines parent AMR Corp. hit their lowest point since 2003 as hit their lowest point since 2003 as uncertain prospects for a contract with pilots raised fresh doubts about whether the company can corral labor costs.

AMR's stock has fallen about 40 percent in the fourth quarter as the labor standoff and high fuel prices stoked fears of a bankruptcy filing that could wipe out shareholders. The shares were down 7 percent in late afternoon trading Thursday.

A spokesman for the Allied Pilots Association said Thursday that there was no support for a company proposal on pay and other conditions. This week, the company offered signing bonuses plus annual raises of 2 to 4 percent in exchange for concessions such as lower rates for flying smaller planes, an end to company-paid retiree health benefits, and work rules including longer hours.

American says costly labor contract rules cause it to spend at least US$600 million more than other airlines, and it's seeking changes to narrow that gap.

The company and the pilots' union have been bargaining since 2006 but stepped up the pace of talks in early October, after AMR stock plunged when news broke about a high number of pilot retirements. Some pilots likely quit to take advantage of a clause in their contract that lets them protect their retirement accounts retroactively from a downturn in the stock market, but investors saw it as a sign of company insiders bailing out.

American says it has agreements with the pilots' union on dozens of contract provisions, but big ones, including wages, are still in play. The company is also negotiating with flight attendants and mechanics.

The lack of key labor deals has rekindled speculation among analysts that AMR could be headed toward a bankruptcy filing. Standard & Poor's analyst Jim Corridore said this week that large pay increases for pilots "would be a move in the wrong direction" unless accompanied by major improvements in productivity.

AMR shares fell 12 cents, or 7 percent, to US$1.70 late in the afternoon. Earlier in the session, they bottomed at US$1.63, the lowest price since March 2003, when the company teetered on the brink of bankruptcy.

The shares had dropped 77 percent this year through Wednesday's close. By comparison, shares of United Continental Holdings Inc. had dropped 29 percent and Delta Air Lines Inc. had fallen 40 percent.