Air France-KLM said its losses mounted sharply in the first quarter compared with a year earlier, when earnings were boosted by a gain in the value of oil price hedging contracts the airline uses to manage its fuel costs.
The group said it lost 630 million euro (£531 million) in the January-March quarter, compared with a loss of 379 million euro (£319 million) a year earlier. Last year's result benefited from a 220 million euro (£185 million) gain on the airline's hedging contracts.
The airline, in the midst of a three-year turnaround plan, said it is hoping to strengthen its position by paying down debt and reducing staff costs further.
Air France-KLM is struggling to compete against low-cost carriers and has said it expects to cut about 5,000 people in its workforce of 49,000.