BERLIN, Dec 16 (Reuters) - Daimler Truck (DTGGe.DE), Traton (8TRA.DE) and Volvo (VOLVb.ST) have signed off plans announced in July for a joint venture to set up a high-performance electric charging network for trucks and buses across Europe, the companies said on Thursday. The three firms will invest 500 million euros ($565.10 million) to set up and operate at least 1,700 high-performance charging points near motorways and logistics hubs within five years, with operations set to commence in 2022. The venture is still awaiting approval from authorities, the statement said. ($1 = 0.8848 euros)