Malaysia Airlines Berhad (MAB) Thursday announced that it had signed a long-term lease agreement for four new Airbus A350-900s with Air Lease Corporation (ALC). The A350-900 aircraft were ordered by ALC and will be delivered by Airbus between the fourth quarter of 2017 and the second quarter of 2018, the company said in a statement. "We are excited to have this aircraft as part of our fleet," said MAB CEO Christoph Mueller. The long-term lease agreement came as the beleaguered carrier began operating on Sept. 1 under the new company, MAB, as part of a $2 billion rehabilitation program. Malaysia Airlines suffered two deadly air tragedies last year, with the disappearance of the Beijing-bound flight MH370 on March 8, 2014, and the downing of flight MH17 in eastern Ukraine a few months later.