United check-ins slowed as airline reservation system goes down

United Continental Holdings Inc. experienced a major passenger reservation system failure that has blocked automated check-ins at airports and affected its website, according to FlightAware.com.

The airline confirmed a network outage affecting airports and its website Tuesday, without offering any specifics.

“We are working to resolve the issue and minimize any impact to our operations,” said Mary Ryan, a spokeswoman for Chicago-based United.

United can check in passengers manually while working to get its system back online, FlightAware.com Chief Executive Daniel Baker said.