BRUSSELS, Sept 20 (Reuters) - A cyberattack at a service

provider for check-in and boarding systems has disrupted

operations at several major European airports including London's

Heathrow, Brussels and Berlin, causing flight delays and

cancellations on Saturday.

Collins Aerospace, which provides check-in and boarding

systems for several airlines across multiple airports globally,

is experiencing a technical issue that may cause delays for

departing passengers, London's Heathrow Airport said on

Saturday, having warned of delays.

RTX, Collins Aerospace's parent, was not immediately

available for comment outside of U.S. business hours.

The attack has rendered automated systems inoperable,

allowing only manual check-in and boarding procedures, Brussels

Airport said on its website.

"This has a large impact on the flight schedule and will

unfortunately cause delays and cancellations of flights...The

service provider is actively working on the issue and trying to

resolve the problem as quickly as possible."

Passengers with a flight scheduled for Saturday were advised

by the affected airports to confirm their travel with airlines

before heading to the airport.

"Due to a technical issue at a system provider operating

across Europe, there are longer waiting times at check-in. We

are working on a quick solution," Berlin Airport said in a

banner on its website.

Frankfurt Airport, Germany's largest, was not

affected, a spokesperson said. An official from the operations

control centre at Zurich Airport also said it had not been

impacted.