German air traffic controllers have fixed technical problems that were set to cause disruptions in European airspace on Wednesday, air traffic control firm DFS said.
"From 9 am, we will resume work with 100% of air traffic," said a spokesperson for DFS, whose controllers monitor take-offs and landings at the 15 designated international airports in Germany.
It was too early to say how many flights had been affected by the disruption, the spokesperson added.
German flagship carrier Lufthansa said it had expected delays and cancellations to destinations in Germany and Europe, particularly at its Frankfurt hub, where it is the biggest airline.
It did not say how many flights could be affected. The departures board on Frankfurt airport's website showed around 20 cancelled flights between 7.30 am and 9 am local time (0530 GMT to 0700 GMT)
Earlier, the operator of Germany's busiest airport in Frankfurt had warned that the problems would impact flights across Europe.
On its website, Fraport referred to "technical difficulties" at the DFS air traffic control centre in Langen near Frankfurt, without being more specific.
Source: Reuters