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An outage at a key, but little-known airline booking system delayed check-ins Thursday on dozens of flights around the world.
Spanish company Amadeus IT, which provides a reservation management system to more than 120 airlines worldwide, told CNBC it "experienced a network issue that caused disruption to some of our systems" on Thursday morning.
Service was restored shortly afterward and is now "functioning normally" the company said.
The outage had affected airlines including , Southwest Airlines, Qantas, and Qatar Airways. Singapore's Changi airport tweeted that boarding passes had to be issued manually due to the breakdown.