Spain's biggest airline Iberia cancelled nearly a third of flights Sunday, after pilots went on a 24-hour strike in protest at the creation of a subsidiary budget airline, according to dpa. Some 100 flights were cancelled, affecting 12,000 passengers. The pilots' union, Sepla, estimated that all pilots obeyed the strike call. Iberia said that 98 per cent of passengers had been rebooked on other flights, or provided with alternative transportation. However, there were reports of long queues as passengers attempted to switch tickets. Another strike is planned for December 29. In April, Iberia is due to launch Iberia Express, specializing in flights within Spain and across Europe, while its parent company concentrates on more lucrative transatlantic routes.