Pilots of Spain's biggest airline Iberia on Wednesday announced they would strike on December 18 and 29 to protest plans for the creation of a low-cost subsidiary, dpa reported. The trade union Sepla says the new carrier, Iberia Express, will endanger jobs, salaries and working conditions. Iberia wants the subsidiary, which is to be launched in April 2012, to cover national and European routes, so that the mother company can focus on lucrative trans-Atlantic flights. Negotiations between the company and the union concluded without results, Sepla representative Justo Peral said. Iberia cabin personnel have rejected a call from the pilots' union to join the strike.