NINGBO - Seven Chinese cities agreed on Saturday they would form a joint campaign to inscribe the ancient maritime Silk Road into the UNESCO World Heritage list.

The seven port cities, namely Beihai, Guangzhou, Quanzhou, Ningbo, Yangzhou, Penglai and Zhangzhou, signed a program of action at a forum in east China's Zhejiang Province, pledging to cooperate on the application efforts.

A platform will be built to facilitate governments, museums, and cultural relics authorities of the seven cities to co-study and preserve cultural heritages related to the ancient trade route, said the agreement.

The seven cities served as important export ports in Chinese history, from which silk and porcelain products started to be shipped to regions as far as east Africa more than 2,000 years ago.