LONDON (Reuters) - Hydrogen plane startup ZeroAvia said on Wednesday it had secured $24.3 million in a third funding round from investors, including British Airways, which it will use to develop a regional zero-emissions aircraft that can seat more than 50 people. The latest round was led by property tycoon Li Ka-shing’s investment vehicle Horizons Ventures, an existing investor. Other existing investors, including Bill Gates’ Breakthrough Energy Ventures and energy giant Royal Dutch Shell also joined this funding round for ZeroAvia. The company has been running test flights of a six-seater propeller plane powered by hydrogen. “This new funding... will significantly accelerate our path to zero-emission solutions for larger regional aircraft at a commercial scale,” Val Miftakhov, Chief Executive and founder of ZeroAvia, said in a statement. Including a grant from the British government, ZeroAvia has so far raised nearly $74 million. Backers for the California-based startup’s last funding round in December also included Amazon AMZN.O. In December, ZeroAvia also teamed up with British Airways to explore how the carrier could shift to hydrogen-powered planes in future. British Airways CEO Sean Doyle said in a statement that hydrogen “has the potential to enable us to reach true zero emissions on short-haul routes by 2050.” Hydrogen, which produces water when it burns, is seen as a potential alternative for the aviation industry, a major user of fossil fuels. Hydrogen can be made from fossil fuels or from water using electrolysis, although this is an expensive process. ZeroAvia, which has been conducting test flights in Britain, aims for commercial flights of up to 500 miles using 10- to 20-seat aircraft by 2023 and commercial jets able to haul up to 200 passengers 3,000 miles by 2030.