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.