Tesla plans to increase its production capacity for certain car parts at its $2 billion factory in China, according to a government document seen by Reuters, as it pushes to localise its supply chain in the world's biggest auto market. The US automaker, which started delivering Model 3 electric sedans from its Shanghai factory in December, plans to add lines to make more battery packs, electric motors and motor controllers, according to the document submitted by Tesla to the Shanghai government. Tesla, which by the end of December used about 70 per cent imported parts for the cars it made in China, did not respond to a request for comment. But according to the document, Tesla wants to almost double its annual building capacity for cooling pipes, a key part in a car's heat management system, to 260,000 sets a year, from 150,000. It did not provide capacity details for other parts. The planned production line will not include battery cell manufacturing but will package outsourced battery cells at the plant, the document said. Tesla has previously said it wants to localise its entire supply chain in China by the end of this year. The company is also building an additional stamping line to speed up car production in Shanghai. The Shanghai factory is key to Tesla's growth strategy. It aims to produce 150,000 Model 3 sedans and later hike output to 250,000 a year, including the Model Y, at the facility. The company aims to deliver more than 500,000 vehicles globally by the end of 2020. Tesla's production and delivery plans in Shanghai, however, have been disrupted by a coronavirus outbreak that has killed more than 3,100 people in the world's second-largest economy. Passenger car retail sales in China plunged around 80 per cent in February due to the epidemic, industry data shows. But infections are now reportedly slowing in China, where the deadly virus first originated before rapidly spreading around the world. Factories and other businesses have also been gradually resuming work as the rate of the infections slowed.