CHICAGO (AP) _ Hundreds of flights were canceled or delayed for hours at O'Hare International, but a union official denied reports that it was caused by a work slowdown by air traffic controllers.

No safety problems were reported from Monday's delays and cancellations.

The Chicago Tribune quoted controllers at the Federal Aviation Administration's center in Elgin as saying they expanded the normal spacing between airplanes heading to O'Hare.

They said it was in response to what they consider strict tactics used by a new manager in dealing with controller errors, scheduling and other issues, according to the newspaper.

But Mike Egan, vice president of Air Traffic Controllers Local C-90, attributed the delays to high wind at upper altitudes and the use of two rather than three runways at O'Hare.

``There's been a finger pointed at the controllers here and that's not the case at all,'' Egan told WLS AM.

FAA officials also had blamed Monday's delays on ``strong upper-altitude winds,'' despite reports of calm conditions for air travel across most of the country. Calls to the FAA's regional office in Des Plaines for additional comment were not returned Tuesday.

Flight operations at O'Hare were normal Tuesday morning, said Monique Bond, spokeswoman for Chicago's Aviation Department

Monday's delays were an added blow to travelers returning to O'Hare and other cities after being slowed or stranded during the weekend by bad weather in the East.

United Airlines canceled 116 flights, or 20 percent of its schedule, between 3 p.m. and 8 p.m. Monday at O'Hare. American Airlines canceled more than 20, a spokeswoman said.

United spokesman Joe Hopkins said Monday's delays were ``not related to the weather'' or to its pilots' recent refusals to work overtime.

In a statement, the FAA and the National Air Traffic Controllers Association said they regretted the ``delays that impeded air traffic in the Chicago area.'' The two agencies did promise to ``examine the issues that led to the disruption at the facility, and will take appropriate action.''

FAA spokesman Bill Shumann declined to comment further, and messages left Tuesday afternoon at the National Air Traffic Controllers Association in Washington were not returned.