Lufthansa pilots have decided to go on a three-day strike starting Wednesday, which is supposed to affect 3,800 flight and 425,000 passengers. Pilot union Vereinigung Cockpit decided to go on strike to protest changes to retirement benefits. The union, which represents pilots who fly for Lufthansa and its cargo and Germanwings units, has been in talks with airline management regarding retirement benefits but failed to make progress over the weekend. The union and management have both said they are open to talks to avert the strike. Lufthansa said it would begin to inform passengers of the possible strike via text message and email. While 3,800 flights have been cancelled in anticipation of the strike, 500 Lufthansa and Germanwings flights will operate, the airline said. Lufthansa expects the strike to impact profits "in the range of tens of millions of euros." "The announcement alone has already caused significant damages since passengers have already rebooked flights and logistic customers have made arrangements with other cargo airlines to secure the transport of their goods," it said in a statement. Lufthansa and the union have been bickering over pay levels for two years now, and recent changes to pension and retirement benefits have made things worse. The union, apart from protesting the changes to retirement benefits, has asked Lufthansa to increase wages by 4.6 percent for May 2013 to April 2014, and for a retroactive raise of 5.2 percent for the previous year. This is not the first time Lufthansa and German airports have faced a strike. In February, a strike by security personnel crippled traffic at Frankfurt international airport, costing Lufthansa some $4.1 million. A ground personnel strike on Thursday at seven German airports led to the cancellation of 600 Lufthansa flights.