JAKARTA (Reuters) - Indonesia's central bank unexpectedly cut policy rates on Wednesday, resuming its monetary easing aimed at propping up growth in Southeast Asia's largest economy despite financial market volatility that has weakened the currency.

Bank Indonesia (BI) cut the benchmark 7-day reverse repurchase rate by 25 basis points to 5.75%, its first cut since September.

All 30 economists polled by Reuters had expected no change in rates, citing the pressure on the rupiah.

The bank also trimmed its deposit facility rate and lending facility rate by 25 basis points each to 5.00% and 6.50%, respectively.

Governor Perry Warjiyo said the decision was in line with expectations of low inflation in 2025 and 2026 and the need to support growth.

BI cut interest rates for the first time in more than three years last September, but had then held policy steady at subsequent meetings in 2024 to anchor the rupiah, which has been under pressure amid uncertainty about U.S. policy under President-elect Donald Trump.

The rupiah, which had traded at its weakest level since July last year ahead of the decision, extended losses to 16,320 per dollar after the rate cut.

Inflation has been moderate in Southeast Asia's largest economy, with December's annual rate of 1.57% close to the bottom end of BI's 1.5% to 3.5% target range.

BI said economic growth in 2024 may come slightly below the midpoint of its forecast range of 4.7%-5.5%. BI also lowered its 2025 growth outlook to 4.7%-5.5% range from a previous estimate of 4.8%-5.6%.

(Reporting by Gayatri Suroyo, Stefanno Sulaiman, Fransiska Nangoy and Ananda Teresia; Editing by John Mair)