SHANGHAI -- Hundreds of enterprises have signed up to participate in the fourth China International Import Expo (CIIE), according to an official with the CIIE Bureau Tuesday.

Nearly 80 percent of the world's top 500 companies and industry leaders participated in the expo for the second or third time, said Sun Chenghai, deputy director of the CIIE Bureau, at a press conference held in Shanghai.

Before the opening of the third CIIE, nearly 100 exhibitors had already signed with the bureau to attend the expo in the next three years, Wang Bingnan, director of the CIIE Bureau, who is also China's vice-minister of Commerce, announced on Nov 5.

Wang said the early booking is evidence of "recognition of the CIIE and confidence in the Chinese market."