Pay and working conditions at root of the dispute
More than 90 percent of the German flagship carrier's pilots voted in favor of going on strike, union Vereinigung Cockpit (VC), which represents about 5,400 Lufthansa pilots, said on Friday.
"No one of us really wants to strike and we've been negotiating very patiently, but our patience has run out," the pilots' chief negotiator Thomas von Sturm told journalists.
VC board member Ilona Ritter said the union had not set a date yet for the strike, to give Lufthansa time for a new offer, but did not plan, for now, to call it over the Easter holidays.
Lufthansa's passengers were among the worst affected by a strike by security staff at Frankfurt airport, the airline's home base, last month.
The carrier is in the middle of a restructuring programme, dubbed SCORE, which aims to improve operating profit by 1.5 billion euros compared with 2011.
It has already agreed pay deals with ground staff and cabin crew, leaving the pilots as the final major frontline staff group with which it has to reach agreement.
The current dispute concerns both pay increases and so- called 'transition contracts' awarded to pilots retiring before the legal pension age officially kicks in.
As the retirement age of pilots was raised in recent years and now, following a European court ruling, stands at age 65, Lufthansa has terminated a previous transition agreement as per 31 December 2013.
VC, on the other hand, says being a pilot is a stressful job and they should be given the option of retiring early. It says the average age of pilots leaving the company is 59.
On Friday, the union said it would announce any strike action 48 hours in advance to give passengers time to change their travel plans.
"We will reconsider our plans should Lufthansa challenge us," VC board member Ritter said, referring to the Easter timetable.
The airline responded that it had not changed its position and had no new offer. "We call on returning to the negotiation table," a Lufthansa spokesperson said.
Analysts at Barclays estimate Lufthansa's staff costs are 15 percent lower than at Air France, but still around 10-15 percent higher than at British Airways.
Lufthansa shares were down 0.4 percent by 1200 GMT on Friday, underperforming the Stoxx Europe 600 Travel & Leisure index.SXTP which was up 0.4 percent.
The pilots last took strike action in 2010, causing the cancellation of hundreds of flights in a row over shifting contracts to different units within the Lufthansa group with lower pay.