The firm booked €64m in restructuring costs and severance pay, pushing its net losses to €459m (£386m) compared to €394m a year ago.
Cold weather at the start of the year and strike action also held back growth at the firm.
Revenues were stable at €6.6bn, with passenger revenues rising just 0.6 per cent thanks to continued turbulence in the Eurozone economies.
“We took another step towards our target of sustainable earnings improvements in the first quarter. Nearly all the group companies improved their result,” said Simone Menne, Lufthansa’s executive responsible for finances and aviation services.
The airline said it expects higher operating profit and revenue this year as its cost-cutting drive starts to pay off.
“2013 is the year in which we want to show that we are capable of implementing our ambitious plans,” the firm added.