The Lufthansa Group posted an operating loss of €330m for the first three months of 2010, compared to a €44m loss for Q1 in 2009.
Lufthansa said the worse than expected results were due to a rise in fuel costs, a slump in ticket prices and the strike action by Lufthansa and Germanwings pilots.
Operating expenses rose by 14.8% between January and March 2010, to €6.7 billion, outstripping the group's generated revenues of €5.8 billion over the same period.
Lufthansa Passenger Airlines made a loss of €236 million.
Other member airlines of the Lufthansa group also made a loss: Austrian Airlines lost €66 million, Bmi lost €45 million, Germanwings lost €34 million, and Swiss lost €1 million.
The group is optimistic for the business year, however, said Stephan Gemkow, Lufthansa's Chief Financial Officer.
"The executive board of Lufthansa expect a rise in revenue and a positive operating result for the group," said Gemkow.
Traffic revenue rose from €3,813 million in the first quarter of 2009, to €4,576 in Q1 2010.
"A recovery in demand is not enough to secure a good result. Cost efficiency and increasing revenues even further are also absolute musts."
Lufthansa spent €477 million on the expansion and modernisation of the fleet between January and March this year.