China's self-invented passenger plane C919 will take off in 2015, one year later than originally planned, said its manufacturer, the Commercial Aircraft Corporation of China (COMAC), on Wednesday.

COMAC said C919's general assembly and test flight will be delayed until 2015, and it will take another two years before they can deliver the craft to customers. So far, some 380 orders have been placed for China's first jumbo passenger jet, despite the craft still going through a detailed design process.

Analysts believe fierce competition with the world's aviation giants -- Boeing and Airbus -- might have resulted in the delayed C919 delivery. In recent years, Boeing unveiled its 737MAX, whereas Airbus rolled out the A320neo. These respectively upgraded versions of the 737 and A320, the two companies' longstanding single-aisle trunk liners, also squeezed the potential C919 market.

COMAC is additionally encountering trouble purchasing certain parts from different areas of the world, as well as difficulties with the integration of various sub-systems into the plane. These factors too have contributed to the craft’s delayed maiden flight.