Commercial Aircraft Corporpation of China (Comac) signed a contract to sell another twenty C919 jets to BOC Aviation, the plane-leasing arm of Bank of China (3988.HKG), Bloomberg reported. The latest agreement boosts state-owned Comcac’s total order of the mid-sized jet to 235, among eleven state-backed customers. The C919 passed a preliminary technical review last December and is due to make its first flight in 2014 and enter service by 2016. The company is compeating with Airbus (subsidiary of EADS, EAD.EPA) and Boeing (BA.NYSE) to capture rising demand for jets in emerging economies. “China has invested huge money in the project and is determined to make it successful. Domestic airlines and state- backed lessors are likely to keep placing orders” said David Wei, an analyst with Shanghai Securities, adding that the planemaker may struggle to achieve the stated deadlines. Comac expects to reach an agreement with Montreal-based Bombardier within two months for joint development of the C919, said Han Kecen, Comcac’s vice president.