BEIJING, May 14 (Reuters) - China's state-owned aircraft

manufacturer COMAC is working on preliminary designs for a new

widebody jet called the C939, the South China Morning Post

reported, citing a source familiar with the matter.

Commercial Aircraft Corporation of China, which is expanding

production facilities for its C919 narrowbody jets, has sketched

out preliminary designs for the new aircraft, according to the

report published late on Monday.

It would be many years before the early concepts materialise

into a testable prototype, according to the report, which also

did not provide specific details on the proposed plane.

The new jet would expand commercial operations for COMAC

amid ambitions by Beijing to take market share from industry

leaders Airbus and Boeing ( BA ).

The C919 has so far gained more than 1,000 orders, but

mostly from Chinese airlines and aircraft lessors including

China Eastern Airlines, the first user of the jet.

COMAC's other in-development widebody plane, the C929, is

designed to travel international routes of up to 12,000 km

(7,500 miles). It is speculated to be on par with some aspects

of mainstream competitors like Boeing's ( BA ) 787 Dreamliner, a second

source said according to the report, adding that progress was

"in full swing".

China has said it wants to secure broader international

recognition for the C919 this year. Last year, government-backed

media The Paper said China expected to reach annual production

capacity of 150 C919s in five years.