JAKARTA Indonesia posted an August trade surplus of $3.12 billion, roughly double the expected amount, as the drop in imports was larger than forecast, data from the country's statistics bureau showed on Friday.

A median forecast of 19 economists surveyed by Reuters had put Southeast Asia's biggest economy down as booking a surplus of $1.55 billion in August, versus $1.31 billion in July.

Imports in August dropped 14.77% to $18.88 billion, compared to the 9.33% drop expected by analysts, led by declines in the purchase of raw materials and capital goods.

Indonesia's exports dropped 21.21% annually in August to $22 billion, slightly better than the 22% decline expected.

Exports fell amid weaker prices for top commodities like coal, palm oil and natural gas compared a year earlier.

(Reporting by Fransiska Nangoy, Stefanno Sulaiman; Editing by Kanupriya Kapoor and Tom Hogue)