Foreign trade for southwest China's Tibet autonomous region topped $3 billion last year, a year-on-year increase of 152.02 percent, ranking first among China's provincial-level economies.

The figure also led the national average growth rate by 145 percent.

A spokesman for the customs office of the regional capital of Lhasa said exports took up 98 percent of Tibet's foreign trade, adding up to $3.35 billion, a year-on-year increase of 183.58 percent.

The spokesman ascribed the increase in foreign trade to the region's improving transportation, fast development of competitive industries and ethnic handicraft industry and convenient procedures adopted by the customs authorities.

Tibet's foreign trade mainly consists of general trade, as well as small-scale trade in the region's border areas. Its general trade reached $1.73 billion, accounting for 50.53 percent of its total foreign trade and marking a 359.4-percent increase.

Nepal, Malaysia and Indonesia were Tibet's top three trade partners in 2012, recording $1.7 billion, $22 million and $19 million in foreign trade with Tibet, respectively.