* Plane flew for 1 hr, 25 mins from Shanghai
* Third prototype first flew in December
* Fifth and sixth due to fly later in 2H 2019 (Recasts with company confirmation, details on future prototypes)
SINGAPORE/BEIJING, Aug 1 (Reuters) - The fourth prototype of China's home-built C919 narrowbody passenger plane completed its first test flight on Thursday, its manufacturer said, as the country pushes forward with a homegrown rival to Airbus SE and Boeing Co jets.
The test flight from Shanghai lasted for 1 hour and 25 minutes, Commercial Aircraft Corp of China Ltd (COMAC) said on its official account on Weibo, China's Twitter-like social media platform.
COMAC said the programme's fifth and sixth test planes were scheduled to have their maiden flights later in the second half of 2019.
The third C919 prototype conducted its first test flight in December.
The manufacturer is aiming to obtain certification for the plane from Chinese regulators by the end of 2020.
Analysts consider the target ambitious given the test planes have flown relatively few hours since the first C919 flew in 2017.
The C919 has dozens of mostly Chinese customers that have placed orders and commitments for more than 800 jets. (Reporting by Jamie Freed in Singapore and Min Zhang in Beijing; Editing by Muralikumar Anantharaman)