By Lisa Barrington

SEOUL, March 26 (Reuters) - Government-owned Lao Airlines is set to start operating COMAC's C909 regional jet, a spokesperson for the country's flag carrier said, joining several other Southeast Asian nations preparing to add Chinese-made commercial aircraft to their fleets.

A group of Lao Airlines staff was at COMAC's Customer Training Centre in Shanghai this week for training on COMAC planes, photos shared on social media by several employees showed.

A spokesperson for Vientiane-based Lao Airlines confirmed the training and said the airline was expecting to get one C909 around the end of March.

Other social media postings indicate staff from Laos' civil aviation regulator also attended training there this month.

Laos' Department of Civil Aviation (DCAL) did not respond to a request for comment on the training or certification of the C909 in Laos. COMAC did not respond to a request for comment.

The state-owned Chinese planemaker has since the start of last year stepped up marketing to regulators and airlines as it seeks to compete internationally with rivals Airbus AIR.PA, Boeing BA.N and Embraer EMBR3.SA and ramps up production of the C909 and its larger C919 narrowbody jet.

COMAC's C909, previously branded as the ARJ21, is a regional jet that seats up to 90 people and is China's first jet-powered plane to reach commercial production. It entered service in 2016.

The C909 is not as high-profile as COMAC's more advanced C919, but its introduction in Laos would allow the planemaker to gain a foothold in another country and boost its visibility outside China.

Vietnamese budget carrier VietJet VJC.HM has agreed to lease two C909s from China's Chengdu Airlines and is waiting for Vietnam's regulator to authorise the use of Chinese-manufactured planes in the country.

Laos already operates small Chinese-made Xian MA60 turboprop planes. A 2010 memorandum of understanding between the Chinese and Lao aviation regulators shows that Laos recognises China's aircraft design certifications - avoiding the step Vietnam's regulator needs to take.

Indonesia is the only country outside China operating COMAC planes, through Indonesian carrier TransNusa, which flies C909s.

Brunei-based startup GallopAir in 2023 ordered 15 C909s and 15 C919s, in the first non-Chinese C919 order, but has yet to receive authorisation for the C909s from the country's aviation regulator.

In January, the airline chartered a China Southern Airlines 600029.SS C909 to Brunei as trial.

(Reporting by Lisa Barrington; Editing by Jamie Freed)

((lisa.barrington@thomsonreuters.com;))