FRANKFURT, Germany — German airline Deutsche Lufthansa AG has lowered its profit forecast for 2015 over concerns that the global economy may experience a downturn next year.

Lufthansa had previously said it expected an operating profit of 2 billion euros ($2.55 billion) in 2015, but now estimates the result will be “significantly” above this year’s predicted profit of 1 billion euros.

The airline said in a statement Thursday that the revision was “mainly due to a general downturn in the forecasts for global economic growth compared to earlier in the year.”

It says the result will also be affected by higher pension costs.

Lufthansa kept its profit guidance for this year, despite strike-related costs of 170 million euros.

Shares in Lufthansa were down almost 5 per cent at 11.70 euros on the Frankfurt exchange.