NANJING - Investment contracts worth $3.4 billion?were signed by enterprises from both China and the United States during a forum held in eastern China's Jiangsu province.

Eighty-five enterprises from 21 Chinese cities and 20 US cities gathered for the second US-China Cities Forum on Economic Cooperation and Investment that runs from Friday to Saturday.

A total of 42 investment projects were involved, covering 21 sectors -- including manufacturing, energy conservation and environmental protection, electronic information, chemical and pharmaceutical.

China's Finance Minister Xie Xuren said at the opening ceremony that China and the United States share different resource advantages, and strongly complement each other in economic development.

The two economies should expand cooperation in more sectors, especially in energy and environmental protection, biomedicine and infrastructure, so as to turn opportunities into tangible results, Xie said.

The forum, jointly sponsored by Chinese and US finance ministries, this year seeks to form contracts on the basis of spoken agreements reached between China and US top officials over the past year, including Chinese President Hu Jintao's visit to the United States in January 2011.

The forum was first held in Seattle on April 19 and 20 last year.

China and the United States are each's second largest trading partner. Bilateral trade currently totals $446.6 billion.