C H I C A G O, Aug. 5 - United Airlines, the world's largest airline, canceled more than 150 flights at Chicago's O'Hare International Airport today because of crew shortages and bad weather.

"Yes, we had about 156 United flights canceled today because of a combination of weather and crew shortages," United Airlines spokesman Chris Brathwaite told Reuters. "We are trying to get people diverted to other planes."

Brathwaite also said that some pilots, who are in contract talks with the airline, have refused to work overtime since April.
Both the pilots, represented by the Air Line Pilots Association, and United, a unit of Chicago-based UAL Corp., have set Labor Day as the target for finishing negotiations on a new contract, the first since employees took majority control of the company in 1994.

The sticking points are job security, flight assignments, salary and benefits. Negotiations between the two sides became more complicated when UAL announced earlier this year that it planned to acquire US Airways, the No. 6 U.S. carrier.

The Air Line Pilots Association was not immediately available for comment on the cancellations.

Thunderstorms and showers moved into the Midwest this weekend. Weather problems on the East Coast have contributed to the cancellations, Brathwaite said.