Set up by American Airlines and IBM as a passenger reservations system in 1960, the travel technology firm is one of the world's three major global distribution system (GDS) providers alongside Amadeus and Travelport. Global distribution systems power travel agencies, online and offline, and corporate travel bookers worldwide, enabling them to book flights, hotels and car rentals from one place. Sabre Travel Network has a market share of about 15 percent by bookings in central Europe and is hoping to double this within five years, regional head Carsten Schaeffer said. "Ten years ago the GDS market was very stable, there wasn't a lot of movement. But now we're growing here and Amadeus is trying to grow in North America," said Schaeffer, senior director for central Europe and Nordics, adding that both companies were taking market share from Travelport. Sabre's customers in central Europe include Unister, one of Germany's largest ecommerce companies which is known for travel sites such as and Sabre is trying to win new customers - including larger travel agents that use more than one GDS - by adding more suppliers, such as Europe's rail operators. It is also using aggregators and an app to offer more specialist services, such as bus tours or other leisure activities that would otherwise be too time-consuming and costly to integrate into its GDS platform. Like others in the travel industry, Sabre is closely watching the impact of Lufthansa's much debated charge for GDS bookings. The EUR€16 (USD$18) fee for bookings not made via Lufthansa group websites has prompted criticism and complaint from travel technology providers and travel agents. "We don't have a feel yet for what's really happening," Schaeffer said, pointing out that the charge only took effect from September 1 and the picture had been muddied since then by two days of Lufthansa pilot strikes. "But we don't think it's a good move because GDSs create transparency. People want an unbiased overview of the market first." He said time would tell whether the Lufthansa move would prompt others to follow. "If all the carriers have the same demand, the GDSs will respond."