Lufthansa said the orders were worth 14 billion euros ($19 billion) at list prices.
The 777-9X jets from Chicago-headquartered Boeing Co. and the Airbus A350-900 models will begin being delivered in 2016. They will replace older aircraft such as Boeing 747-400s and Airbus A340-300s. The 777-9X family is to launch later this year and enter service around the end of the decade, Boeing says.
Lufthansa said it was taking options to buy more planes if its business needs demanded it. Airbus, based in Toulouse, France, said Lufthansa had options to buy 30 more of the planes.
The company said the new planes will make its fleet more fuel-efficient and quieter as well as improve passenger comfort with wider cabins. CEO Christoph Franz said that the order "enabled a quantum leap in efficiency."
Lufthansa AG is facing tough competition from Middle Eastern airlines on long-haul routes between Europe and Asia, as well as competition from low-cost airlines on shorter routes. Aircraft noise has been a political and legal issue at the airline's Frankfurt hub, where some residents have complained about the impact of new runways.
The airline says the new planes use an average 2.9 liters of jet fuel to fly a passenger 100 kilometers - lower than the current fuel mileage figure for the company's long haul fleet of 3.58 liters per 100 kilometers per passenger.
The company recorded a net loss of 204 million euros ($270.01 million) in the first six months of the year as restructuring costs, fuel prices and slower business in Asia and the Middle East sapped earnings.
Its shares rose 1 percent to 13.98 euros in midday trading in Frankfurt.