A Southwest Airlines jet moves on the runway at LaGuardia Airport in New York. A technical outage Monday is affecting major airlines and causing flight delays that may lead to a ripple effect throughout the day. (Julio Cortez/AP)

Several major airlines nationwide grounded their planes Monday morning because of a software outage.

Greg Martin, a spokesman for the Federal Aviation Administration, said the problem was with a system called Aerodata that’s produced by a vendor to track a plane’s weight and balance. It’s used in flight planning.

Martin said the effect was “minimal” in terms of the number of planes. It affected several airlines, including Southwest, Delta and JetBlue, airline officials said.

“It was out earlier this morning, and it should be back very quickly,” Martin said of the Aerodata system.

Southwest said that it had an “internal ground stop” for about 40 minutes and that “scattered flight delays are anticipated.” It advised customers to check its website for updates.

Delta said in a statement that some of its connecting flights were affected. “No cancellations are expected due to the issue and our teams are working to resolve some resulting delays,” it said.

JetBlue said it, too, had delays on some of its flights because of the Aerodata problem.

United said that about 150 of its flights were affected. “Some flights that were affected have departed, and we’re working to get all affected flights back on schedule,” United said in a statement.

Just after 8 a.m., FlightAware.com said about 100 flights were late or canceled at Baltimore-Washington International, Dulles International and Reagan National airports.

Travelers should check with their airlines about the status of their flights.

Last week, several airlines had trouble after Sabre, a company that airlines use for printing baggage tickets, check-in and making reservations, had technical problems.