Pilots' union Vereinigung Cockpit announced on Friday that talks with Lufthansa had broken down and said a response would follow "immediately".
But following a meeting on Monday it was still unclear when a strike might begin. A spokesman for the union said: "It's about balancing passengers' interests with the effectiveness of a strike."
The union will want to hit Lufthansa with a strike during a busy period to prevent them finding enough cover.
The dispute centres on the pension arrangements of 5,400 pilots at Lufthansa and German Wings.
Lufthansa wants to raise the retirement age for its pilots from 59 to 65, while the union wants Lufthansa to keep paying transition money to those who retire before 65.
The disagreement led to a three-day strike in April which grounded 3,800 flights and affected 425,000 passengers.
After the April strike, negotiations started again but broke down on Friday, Cockpit announced.
A spokesman for Lufthansa said: "We really regret Cockpit's decision to declare the talks over."