KUALA LUMPUR (REUTERS) - Malaysia's central bank maintained its key interest rate at 3.25 per cent on Wednesday as expected, and kept unchanged a reserve requirement ratio that it cut in January.

"Overall investment will continue to be supported by the implementation of infrastructure development projects and capital spending in the manufacturing and services sectors,"Bank Negara Malaysia (BNM) said in a statement. "The external sector is expected to record a modest improvement and provide additional support to the economy," the central bank added.

In January, BNM announced an unexpected move to cut the statutory reserve requirement ratio (SRR) to 3.5 per cent from 4.0 per cent to boost liquidity.

All 11 economists in a Reuters poll had expected BNM would keep the overnight policy rate unchanged on Wednesday.

BNM last revised the benchmark rate in July 2014, when it was raised by 25 basis points from 3.0 per cent to curb rising household debt.

Wednesday's policy meeting was the last for BNM's respected governor, Zeti Akhtar Aziz, who has helmed the central bank since 2000. Her current terms ends April 30. The government has not named a nominee to succeed her.

The meeting took place at a time the ringgit has been performing well. The currency, which lost 18.5 per cent against the dollar last year, has strengthened about 4 per cent this year.