Original: By the early 1990s, it became clear that the new Airbus A320 was a serious threat to Boeing's market share, as Airbus won previously loyal 737 customers such as Lufthansa and United Airlines.
Simplified: By the early 1990s, it became clear that the new Airbus A320 was a serious threat to Boeing's market share. Airbus won previously loyal 737 customers such as Lufthansa and United Airlines.