JAKARTA - Indonesia swung back to a trade surplus in August after posting a deficit a month earlier, data from the country's statistics bureau showed on Monday.

Southeast Asia's largest economy recorded an $85.1 million surplus in August, the bureau said, compared with a trade deficit of $64 million in July. A Reuters poll of economists had forecast a $190 million surplus for August.

Exports fell 9.99% in August on a yearly basis to $14.28 billion, compared with the poll's prediction for a 6% fall. Shipments of most non-oil and gas fell on an annual basis, including proceeds from mining which fell 22.45% in August from a year earlier.

"Efforts to boost exports are facing an extraordinary challenge because of a global economic slowdown and with partner countries like Singapore and China facing a slowdown while commodity prices are fluctuating as well," Suhariyanto, the statistic bureau's chief, said. August imports were $14.20 billion, 15.60% down from a year earlier, falling faster than the poll's 12.90% forecast.

(Reporting by Nilufar Rizki, Maikel Jefriando; Writing by Tabita Diela; Editing by Ed Davies and Muralikumar Anantharaman) ((tabita.diela@thomsonreuters.com; +622129927621;))