SEOUL/BEIJING, March 26 (Reuters) - Chinese state-owned

planemaker COMAC's first wide-body jet is in its "detailed

design stage", an executive said on Tuesday, following a report

from the jet's fuselage manufacturer aiming to deliver the first

fuselage section by September 2027.

China, through the state-owned Commercial Aircraft

Corporation of China (COMAC), has invested heavily in its

attempt to break into a passenger jet market dominated by

Western planemakers Boeing ( BA ) and Airbus.

COMAC has so far put the narrow-body C919 and regional jet

ARJ21 into commercial operation, but its long-haul wide-body

program has experienced delays. This included Russia in 2023

dropping out of a joint venture to develop the plane.

The C929 has entered the detailed design stage, COMAC

marketing director Zhang Xiaoguang told a conference in Shangahi

on Tuesday, local media reported.

In February Huarui Aero, the Chinese manufacturer selected

by COMAC in 2021 to build the C929 fuselage, said the first

"middle section of the fuselage" will be delivered in 2027, by

Sept. 1.

This appears to be the first indication of a production

timeline for the C929 since Russia left the project - formerly

known as the CR929.

COMAC did not respond to a request for comment.

The C929 will have around 280-400 seats and a range of

12,000km, COMAC says.

Amid a global shortage of new aircraft, China has said it

wants to advance COMAC's footprint domestically and

internationally this year.

This includes a push for approval from Europe's air safety

regulator for the C919, which is currently only certified by

China.

Industry sources have generally welcomed COMAC's entry into

the market, but caution that building competitive planes is a

long project and have warned the landmark approvals from Western

regulators could take years.

Only the ARJ21, of which COMAC has delivered 128, operates

outside of China, with Indonesia's TransNusa.

COMAC's planes also rely heavily on Western-designed parts.

The C919 engines are supplied by CFM International, a joint

venture between GE and Safran, but Aero Engine

Corporation of China (AECC) is developing a domestic substitute

that has not yet been certified.

China is also working on a domestic wide-body engine.

A COMAC representative at the Singapore Airshow last month

said the C929's engine had not yet been chosen.