UPDATED: 4/16/2013 – 5:44 p.m.

CHICAGO (CBS) — Computer problems at American Airlines are affecting thousands of passengers in Chicago as well as across the nation and worldwide.

American Airlines computer system were restored at 3:30 p.m. Chicago time, after being down for several hours, according to a American Airlines Facebook update. The update said to continue to expect delays and cancellations throughout the day, however.

The airline said on Twitter it expects normal operations on Wednesday, with only a few cancellations.

CBS 2’s Dorothy Tucker reports the glitch led to long lines and confusion at the American Airlines terminal at O’Hare International Airport.

“It’s very frustrating, and … of course we made hotel reservations, and there’s no refund. So we’re hoping we still get on, because we’re on our way to San Francisco, and we’d hate to be out $300,” Ginny Hubbard said.

Josh Hammer had flown into O’Hare from the United Kingdom, and was supposed to catch another flight, but was stuck at the airport.

“I was supposed to catch a connection to Arizona. … Here I am,” he said.

Hammer said it drove him crazy when he called American Airlines about his flight and the operator hung up on him.

Some passengers told WBBM Newsradio that they were sitting on planes for two hours or more.

“American’s reservation system is experiencing intermittent outages. We’re working to resolve the issue as quickly as we can. We apologize to our customers for any inconvenience,” said American spokeswoman Mary Frances Fagan.

As of mid-afternoon, American had canceled more than 720 flights nationwide, including 200 in Chicago. Aother 765 flights nationwide were delayed because of the glitch.

American was giving its passengers several options:

We have made several options available to our customers:

–If customers must travel on Tuesday, and are already at the airport, they can rebook on another airline, by visiting an American Airlines agent or by going to the other airline’s ticket counter with their electronic ticket number.
–If customers must travel Tuesday, but have not yet reached the airport, they can rebook through the American Airlines reservation system, or through another airline, and American will make up the difference in cost.
–If a customer can change their travel to another date, American will not charge them a fee to change their reservation, or will provide a full refund.

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