Aerial photo taken on Sept. 11, 2020 shows the city view of Shenzhen, in south China's Guangdong Province. (Xinhua/Mao Siqian)

The southern Chinese metropolis of Shenzhen saw foreign trade grow 15.2 percent year on year to 2.51 trillion yuan (about 393 billion U.S. dollars) in the first three quarters of this year, local customs said.

During the January-September period, exports rose 13.5 percent year on year to 1.35 trillion yuan while imports jumped 17.2 percent to 1.16 trillion yuan, said Shenzhen Customs.

The top ten trading partners of the manufacturing hub, which borders Hong Kong, contributed to 77.3 percent of the total trade, with trade with the Association of Southeast Asian Nations and the European Union seeing double-digit growth.

Privately-owned businesses contributed to 1.54 trillion yuan of the trade. It is up 17 percent year on year, accounting for over 61 percent of the total trade, said the customs. The proportion rose by one percentage point from a year ago.

Mechanical and electrical products accounted for nearly 80 percent of both exports and imports during the nine months.