Lufthansa Group has identified its "capacity discipline", accompanied by falling oil prices, as a factor in its adjusted EBIT increasing 55% to €1.82 billion ($2.04 billion) in 2015.
Revenue grew 6.8% to just over €32 billion.
The Star Alliance carrier group's passenger airlines more than doubled earnings to €1.5 billion, largely as a result of lower fuel costs.
But chief executive Carsten Spohr says the result also reflects "favourable developments in our passenger volumes and to our capacity discipline". He reiterates that "we will only grow capacity where our cost structures are competitive".
Net profit grew to just under €1.7 billion from €55 million in 2014.
Adjusted operating profit was up 143% at €970 million for Lufthansa's mainline. This figure includes the earnings of budget units Eurowings and Germanwings.
From this year, Eurowings' results will be separately reported. Lufthansa says Eurowings exceeded its target of breakeven in 2015 and generated an adjusted EBIT of €8 million on revenue of €1.9 billion.
Swiss's earnings increased 54% to €429 million, while Austrian Airlines' adjusted EBIT grew nearly sixfold to €52 million.
Lufthansa Cargo's earnings declined 40% to €74 million. The group says that "sizeable overcapacities" in the air freight market led to lower yields and load factors.
Maintenance unit Lufthansa Technik's operating profit rose nearly by a fifth to €454 million. But the group warns that the MRO division's earnings are set to "significantly decline" in 2016 as a result of "increased cost pressure" and expenditure for "growth projects".
Earnings will likely deteriorate at catering unit LSG too, says Lufthansa. Last year, LSG's adjusted EBIT grew 12.5% to €99 million.
Industrial action by flight attendants during the fourth quarter of 2015 reduced earnings by around €100 million, says Lufthansa
For 2016, the group expects its adjusted operating profit to "slightly improve", with passenger airlines as "prime drivers" of growth.
However, Lufthansa warns that "yields are likely to decrease significantly" as a result of "intensified competition" and expansion of Eurowings' long-haul operation.
"We will not be unduly influenced by the current low fuel costs," says finance chief Simone Menne. "We must lower the unit costs at our hub airlines."
For Swiss, the group foresees a "slightly" lower operating profit in 2016 as a result of the Switzerland's "currency situation".
Austrian's adjusted EBIT is set to "significantly" improve, the group predicts.
Eurowings, it forecasts, will make a loss owing to investments in the budget carrier's expansion.
Source: Cirium Dashboard