Spain's Iberia is in merger talks with British Airways
Unions representing Spanish airline Iberia's cabin crews have announced a further eight days of strikes unless a pay agreement can be reached.
The dates for the proposed strikes are 30 November to 2 December, and 14 December to 18 December.
The airline has already been forced to ground hundreds of flights this week due to strike action.
Cabin staff are in dispute with the airline's management over plans for a hiring and wage freeze.
Cabin crews also staged strikes in October.
Most of the affected flights have been short and medium-haul.
"We have called for eight more days because there is no will to reach an agreement," the Sitcpla union said in a statement.
"Our wages have been frozen since 2005 and, according to the company's viability plan, this will continue until 2011."
Iberia wants to reduce costs to combat falling profit. The company made a loss of 165.4m euros ($237.2m; £145.7m) in the first half of the year.