American Airlines said Wednesday that it has struck a deal with one of its labor unions that has a significant presence in Chicago.

The airline and the Transport Workers Union reached a tentative four-year pact for the fleet service and ground service employees, who load and unload baggage, de-ice aircraft, clean plane cabins, direct aircraft on the ground and complete other "under the wing" jobs.

The new contract, to be voted on by members over the next month, would cover some 11,000 workers nationwide, including more than 1,400 at O'Hare International Airport.

The deal provides employees with higher pay and other enhancements such as additional holidays, sick time and vacation.

In return, the company hopes to get better productivity from employees and will be able to outsource the airplane cabin cleaning and fueling work. Employees doing those jobs will be reassigned to other duties, the airline said.

"This agreement is a significant step in our efforts to achieve the competitive costs that are critical to our future success," American Airlines said in a statement. The airline has blamed its poor financial performance on labor contracts that are richer than rivals'.

The proposed pact includes a 6 percent lump-sum signing bonus, an immediate 3 percent base pay increase and three 2 percent increases that would take effect 12 months, 24 months and 36 months after ratification.

"If this agreement is ratified, it will provide significant pay increases to fleet service and ground service workers," said Donny Tyndall, president of TWU Local 502, representing union members in Los Angeles, Las Vegas, Phoenix, San Diego, Santa Ana, Calif., and Tucson, Ariz. "The local presidents who were at the bargaining table agreed that we should send this tentative agreement to our rank-and-file members for their decision."

Under terms of the tentative agreement, a typical fleet service clerk will earn more than US$23 per hour by the end of the four-year contract, while a crew chief will earn more than US$25 an hour.