By Stefanno Sulaiman and Gayatri Suroyo

JAKARTA Indonesia's trade surplus shrank more than expected in July to $1.31 billion, as imports contracted less than predicted, data from the statistics bureau showed on Tuesday.

A Reuters poll of economists had expected a July surplus of $2.53 billion. Trade surplus in the previous month was $3.46 billion.

Southeast Asia's largest economy booked its biggest ever trade surplus last year as exports jumped, driven by a global commodity boom.

The surplus has narrowed this year as exports declined amid falling commodity prices.

Shipments from Southeast Asia's largest economy plunged 18.03% on a yearly basis in July to $20.88 billion, roughly in line with the poll's prediction of an 18.30% drop, as prices of its top commodities like coal and palm oil fell.

Imports dropped 8.32% on a yearly basis to $19.57 billion, compared with the 15.50% fall predicted by economists in the poll.

(Reporting by Stefanno Sulaiman, Gayatri Suroyo and Fransiska Nangoy; Editing by Martin Petty)