Xstrata, the global diversified mining group and the world's largest coal exporter, opened its first office on the Chinese mainland in Shanghai on Tuesday.

"Establishing a permanent presence in Shanghai will better enable us to source high-quality mining equipment from China and other Asian countries for our coal, copper and nickel businesses around the world," said Rob Sutton, general manager of the office, which is under the name Xstrata Commercial Services (Shanghai) Co.

Sutton said China has been an important market for Xstrata, with copper sales in China taking up a third of its global sales.

"We are currently expanding a number of our existing mines around the world, as well as making major investments in new mines, some of them particularly designed for the Chinese market," he added.

Xstrata has been cooperating with about 40 Chinese suppliers on its procurement of materials and Sutton said the number will definitely grow with the opening of the new office, especially on its coal processing activities.