BEIJING—Chinese regulators said on Saturday Tesla Inc would recall nearly 300,000 China-made and imported Model 3 and Model Y cars for an online software update related to assisted driving, with owners not required to return their vehicles. The State Administration for Market Regulation said on its website that the move is linked to an assisted driving function in the electric cars, which can currently be activated by drivers accidentally, causing sudden acceleration. The remote online software recall—a first for Tesla cars built in China—covers 249,855 China-made Model 3 and Model Y cars, and 35,665 imported Model 3 sedans. Tesla, now making Model 3 sedans and Model Y sport-utility vehicles in Shanghai, sold 33,463 China-made electric cars in May, according to industry data. By Yilei Sun and Tony Munroe