The adverse balance of trade flowing through Shanghai between China and the Republic of Korea (ROK) has been widening, local customs sources said.

The latest statistics released by the Shanghai Customhouse show that the volume of trade between the countries that traveled via Shanghai stood at US$8.7 billion in the first half of the year, up 68 percent from the same period last year, with China's trade deficit climbing to US$3.44 billion.

Exports accounted for US$2.64 billion worth of goods, up 51 percent, while imports were valued at US$6.08 billion, a rise of 77 percent, according to the customs sources.

Industry experts said that the widening trade deficit was caused by more and more ROK companies moving their production bases to China and exporting most of their products to other countries, including ROK. This has also driven up China's import of raw materials and components from ROK.

Import and export for processing trade between China and ROK via Shanghai Port amounted to US$3.8 billion from January to June, up 77 percent, accounting for 44 percent of Sino-ROK trade.

China's imports from ROK through Shanghai include machinery and electronic products, primary plastics and purified terephthalic acid (PTA), an aromatic acid primarily applied in the production of polyester, garments and textiles, and China's exports to ROK were machinery and electronic products, garments and apparel accessories.