Lufthansa Group's adjusted EBIT rose 75% in the second quarter, to €1.02 billion ($1.2 billion).
Total revenue was up 14% at €9.26 billion, adds the Star Alliance airline group.
Across the six months ended 30 June, adjusted EBIT near-doubled to €1.04 billion on revenue up 13% at €17 billion.
Finance chief Ulrik Svensson states: "In addition to strong demand and a robust pricing environment, this [result] is attributable to the fact that we achieved a further structural reduction in costs."
He warns that efficiency efforts must be continued as "this is the most important way that our margins can be improved sustainably".
Unit costs excluding fuel and currency effects were reduced 3.4% in the second quarter, and 1.2% across the first half, Lufthansa says. Unit revenue, at constant currency, meanwhile increased 1.8% for the quarter and 0.5% afor the half.
Lufthansa's passenger airline grew its first-half adjusted EBIT 58% to €569 million.
For subsidiary Swiss, the same metric was up 47% at €187 million. "Swiss more than offset a decline in yields with a substantial increase in sales," notes Lufthansa Group.
Austrian Airlines' first-half adjusted EBIT swung to a €3 million profit, from a €1 million loss in the same period of 2016.
The group's point-to-point operators, Eurowings and Brussels Airlines, delivered a combined first-half adjusted EBIT of €58 million on the back of a doubling in revenue to €1.8 billion. During the first half of 2016, the comparable figure was negative to the tune of €77 million.
Svensson says Eurowings "now has every prospect of breaking even this year – earlier than anticipated".
The group also foresees Lufthansa Cargo breaking across the full year. It says the freight division's adjusted EBIT of €78 million was a result of "favourable trends in demand" and a 9% improvement in constant-currency yields. The division had made an operating loss of €45 million during the first half of 2016.
For the full year 2017, the group has lifted its adjusted EBIT target above the 2016 result of €1.75 billion. Lufthansa had said in May that it expected to generate a result "slightly below" that threshold.