Daimler board members sit on the podium during the company's annual news conference in Stuttgart, Germany, February 4, 2016. REUTERS/Michaela Rehle/File Photo

STUTTGART (Reuters) - Daimler DAIGn.DE said on Wednesday it aims to start serial production of an electric heavy truck with a range of 200 km (124 miles) in 2021, Daimler Trucks chief Martin Daum said.

A year ago, Daimler had said its eActros could be ready for serial production in 2020.

Ten customers, including supermarket chain Edeka and logistics group Hermes, are to test Daimler’s eActros truck this year, Daum said. After that, another set of customers will test it for another year.

Daimler and rivals including Tesla TSLA.O and Volkswagen's VOWG_p.DE MAN are racing to bring electric trucks to market to cope with a push to shift from fossil fuels to greener vehicles and reduce pollution.