German airport operator Fraport cut its guidance for passenger number growth at Frankfurt to under 4 percent in 2012 after a series of strikes hampered operations and put people off flying through the airport.
"Guidance might be influenced negatively by further strike action," Fraport said on Thursday as it reported a 13 percent rise in core profit for 2011.
Fraport had previously expected passenger numbers at Frankfurt to grow at the lower end of a 4-7 percent range.
Frankfurt Airport is Europe's third busiest after London Heathrow and Paris Charles de Gaulle, in terms of passenger numbers.
Apron staff who guide planes in and out of parking positions staged a series off walkouts last month, resulting in the cancellation of nearly 2,000 flights, before a court brought a halt to the action.
The GDF union has not ruled out further strike action in the dispute over pay and conditions.
Lufthansa, which accounts for around 60 percent of Frankfurt's 1,300 flights a day, had previously said the strikes were deterring customers from booking flights.
Fraport reported 2011 earnings before interest, tax, depreciation, and amortization of EUR€802.3 million (USD$1.05 billion).
