Fraport Group reported a 17.4% year-on-year fall in profits to €86.9 million ($108 million) in the first half of 2012.
The airport operator attributes the decline to the inauguration of Frankfurt Airport's new runway and continuing investment for the new Pier A-Plus at Terminal 1.
Revenue for the six months to 30 June rose 2.5% year-on-year to €1.15 billion, as EBITDA (earnings before interest, taxes, depreciation and amortisation) increased 2% to €366 million.
Passenger numbers at Frankfurt airport during the period increased 3.4% year-on-year to 27.4 million, despite industrial action in February and March which led to a cancellation of 2,150 flights.
Total passenger numbers at all five of the airports managed by Fraport - Frankfurt, Antalya, Lima, Burgas and Varna - increased 2.8% year-on-year to 44.2 million passengers.