FRANKFURT (Reuters) - Daimler said it will invest 2.6 billion euros ($3.2 billion) in research and development at its trucks division by 2019, as part of a broader effort to mass produce electric heavy-duty commercial vehicles from 2021.

Mercedes-Benz is currently testing eActros trucks with an operating range of up to 200 kms (125 miles) as part of a broader electrification push, Daimler said.

"In 2018 and 2019, Daimler Trucks will invest approximately 1.3 billion euros on average each year in research and development," Daimler said in a statement on Wednesday.

Daimler Trucks will focus on developing electric mobility, connectivity and automated driving technology for commercial vehicles, the company said.

Mercedes-Benz is testing trucks with 11 battery packs and two drive motors until 2020 to see if fully electric vehicles can replace diesel-powered equivalents, the company said.

Mercedes-Benz is testing two variants with a gross vehicle weight of 18 to 25 tonnes and will hand them over to a focus group of customers this year.

(Reporting by Edward Taylor; Editing by Adrian Croft)