The maiden test flight of China\'s first large commercial jetliner has been delayed to 2015 due to development difficulties, state media reported Wednesday, in a setback for the country\'s aviation ambitions. The 168-seater C919 is a symbol of national pride, planned by the state-backed Commercial Aircraft Corporation of China (COMAC) as a challenge to the dominance of international aviation giants Boeing and Airbus. But carrying out the first test flight as planned next year is not possible, the China Daily newspaper reported, citing a COMAC official it said declined to be identified. The plane\'s first delivery to customers, planned for 2016, may also be delayed, the paper cited the official as saying. But Wang Ya\'nan, deputy editor-in-chief of Aerospace Knowledge magazine, expected a longer delay. \"The earliest time for its delivery to buyers is likely to be in 2018 or 2019,\" Wang said, according to the paper, adding that authorities in China and abroad would need two to three years to certify its airworthiness. By the end of last year, at least 15 mostly Chinese companies had agreed to purchase 380 of the planes, the China Daily said. The plane\'s development comes as China\'s rapid economic growth creates huge demand for aircraft as growing incomes boost air travel. US aviation giant Boeing has estimated China will need 5,260 commercial jets over the next two decades. The C919 would compete with Boeing\'s 737 and the A320 of European consortium Airbus. COMAC has said the aircraft will have \"Chinese characteristics\" but it is relying on foreign technology for key parts, including the engines and central wing box, which secures the wing in the body. Zhang Yanzhong, director of the project\'s advisory committee of experts, cited problems related to the manufacturer\'s technical skill levels and experience in building commercial aircraft, the report said. \"Generally speaking, the project is going well now,\" Zhang said, adding that the setbacks encountered were not major.