Iberia pilots last year went on strike when Iberia created a low-cost carrier called Iberia Express.

CNN: Iberia cabin crew strike over layoffs, salary cuts

It launched Iberia Express aiming to cut the costs of operating those routes, an Iberia spokeswoman said.

CNN: Iberia pilots on strike again over new low-cost carrier

Iberia Express currently serves just four routes, all in Spain: Madrid to Palma de Mallorca, Malaga, Seville and Alicante.

CNN: Iberia pilots on strike again over new low-cost carrier

The union has offered for pilots to take deep salary cuts if flying for Iberia Express, but negotiations broke off last month.

CNN: Iberia pilots on strike again over new low-cost carrier

Madrid (CNN) -- Pilots for the Spanish airline Iberia resumed their strikes on Monday, forcing the cancellation of 124 flights, in a grievance over the company's new low-cost carrier, Iberia Express.

CNN: Iberia pilots on strike again over new low-cost carrier