BEIJING (AP) — Tesla Motors Co. and a state-owned Chinese phone carrier announced plans Friday to build 400 charging stations for electric cars in a new bid to promote popular adoption of the technology in China.

Plans call for China Unicom Ltd. to provide space for construction and basic services in 120 cities while Tesla, based in Palo Alto, California, operates the stations. The two companies also will build 20 “supercharger stations” in 20 cities to offer high-speed charging.