(Reuters) -British electric-aircraft developer Vertical Aerospace ( EVTWF ) said on Thursday it has expanded its partnership with helicopter ride operator Bristow Group ( VTOL ) as it aims to bring air taxi services into commercial operation.

Texas-based Bristow Group ( VTOL ) - which offers short-distance helicopter rides in several countries, including the UK and the U.S. - has also placed an order for up to 50 of Vertical's VX4 aircraft, with the option to purchase 50 more.

Air-taxi startups are racing to get approvals and commercialize electric vertical takeoff and landing (eVTOL) aircraft, betting on growing demand for faster, more sustainable urban transportation.