By Sophie Yu and Brenda Goh

BEIJING (Reuters) -China Eastern Airlines, the initial customer for the country's homegrown narrow-body jet C919, will launch the plane's first commercial flight on Sunday, the carrier's app showed on Friday.

The C919 flight will take off as flight number MU9191 at 10:45 a.m. Beijing time (0245 GMT) from Shanghai Hongqiao International Airport and arrive in Beijing Capital Airport at 1:10 p.m.

The commercial operation of the C919 marks a milestone in the country's hopes that the plane will break the longtime Airbus-Boeing duopoly in the world's airline manufacturing industry.

Manufactured by Commercial Aviation Corp of China (COMAC) to rival the Airbus A320neo and Boeing 737 MAX single-aisle jet families, the C919 has made many flights without passengers.

The airline and manufacturer have given its first commercial flight little publicity. But speculation that the flight would happen on Sunday arose on Chinese social media after Shanghai Stamp Collecting Corporation released a photo of a commemorative stamp for the C919 flight that bore a May 28 date.

China Eastern has not said who will fly on the flight and did not respond to Reuters requests for comment on Friday.

Online users said the airline opened an appointment channel earlier this year on its app for the public to book tickets.

China Eastern signed a contract for five C919s in March 2021 in the first commercial deal for the plane. The Shanghai-headquartered carrier received its first C919, numbered B-919A, in December and began 100 hours of empty aircraft verification test flights.

China's Xinhua state news agency had said last year that the C919 would make its first commercial flight in the spring.

The 164-seat aircraft comes with a two-class cabin layout, consisting of business and economy seats.

Although the C919 is assembled in China, it relies heavily on Western components, including engines and avionics, from companies including GE, Safran and Honeywell International.

(Reporting by Albee Zhang, Sophie Yu and Brenda Goh; editing by Gerry Doyle and Jason Neely)