Cofco Ltd, China's largest grains trader, has yet to raise product prices because of government policy, a move that may help the company expand its market share, said Ning Gaoning, company chairman.

Corn prices are at "historically high levels" and the gain in China's food prices is partly because of rising global rates and also strong domestic demand, Ning told reporters on Monday in Hong Kong. China is the world's biggest soybean buyer and second-largest corn consumer.