U.S. automaker Tesla's sales of China-made electric vehicles fell 11.5% to 63,238 units in January from a year earlier, data from the China Passenger Car Association showed on Friday.

Deliveries of China-made Model 3 and Model Y vehicles were down 32.6% from December.

Chinese rival BYD , with its Dynasty and Ocean series of EVs and plug-in hybrids, sold 296,446 passenger vehicles last month, a 47.5% increase on the year, but a 41.8% decline from the prior month.

Last month, the U.S. EV giant launched a revamped version of its best-selling Model Y SUV in China where it is under increasing pressure from challengers such as Xiaomi, the Beijing-based smartphone maker that fast-tracked an EV success.

Xiaomi's electric sedan SU7 outsold the Model 3 in December, and its first SUV is expected to be launched this summer to take on the Model Y.

Tesla planned a suspension of part of the new Model Y lines in Shanghai for upgrades for around three weeks over the Chinese Lunar New Year, Bloomberg News reported.

The biggest annual holiday in China began in late January this year versus February last year, resulting in disruption to production and consumption activity in the first two months.

Tesla has seen its share of China's EV market decline amid intense market competition, while the rollout of discounts and financing incentives in markets including China hurt its profit margin in the fourth quarter.

In addition to an extension of a 10,000 yuan (USD 1,372) discount on outstanding loans for the older Model Y as well as zero-interest financing of up to five years for some Model 3 and older Model Y cars, Tesla announced on Wednesday insurance subsidies of 8,000 yuan for all Model 3 cars in China.

Tesla plans to launch its advanced driver assistance software known as "Full Self-Driving" in China this year.