KUALA LUMPUR, Sept 29 — Malaysia’s ringgit fell, headed for its biggest quarterly loss since 1997, as the relatively low level of import cover afforded by the nation’s foreign-exchange reserves makes the currency more vulnerable to an emerging-markets selloff.

The country’s reserves have declined the most among Southeast Asia’s five biggest economies in 2015 and Moody’s Investors Service said in August that while they are sufficient, their adequacy is the weakest in the region. The holdings recovered for a second straight fortnight in the first two weeks of September, suggesting the central bank scaled back its intervention. The currency slumped to a new 17-year low tomorrow, while government bonds and the benchmark stock index also fell.

The ringgit’s drop was due to “the usual concerns around emerging-market growth and the weakness in equity markets,” said Khoon Goh, a Singapore-based foreign-exchange strategist at Australia & New Zealand Banking Group Ltd. “Although there is already a lot of negative news priced into the ringgit, the fact that Malaysia has the lowest reserve adequacy in the region means the currency is more vulnerable during times of market volatility.”

The currency depreciated for a sixth day and was down 1.1 per cent at 4.4735 a dollar as of 11.29am in Kuala Lumpur, according to prices from local banks compiled by Bloomberg. It earlier reached 4.4765, the weakest level since January 1998, and has plunged almost 16 per cent since June 30.

The ringgit has lost more than any other Asian currency this quarter as a slump in Brent crude weighs on earnings for the region’s only major net oil exporter, just as a looming US interest-rate increase spurs outflows from emerging markets. China’s deepening economic slowdown, a political scandal involving Prime Minister Najib Razak and rising debt at state investment company 1Malaysia Development Bhd. have compounded the losses.

Malaysia’s foreign-exchange reserves rose 0.6 per cent to US$95.3 billion (RM423.04 billion) in the two weeks to Sept. 15 but are still 18 per cent lower than at the end of last year. They were enough to finance 7.3 months of retained imports, compared with 8.4 as of December 31, according to the central bank. The reserves declined to a six-year low of US$94.5 billion in early August.

The cost to insure the nation’s sovereign bonds from default for five years climbed to 238, the highest since 2009, CMA prices show. The credit-default swaps don’t reflect underlying economic strength, Mohd Irwan Serigar Abdullah, secretary general of the Treasury, said in an e-mailed statement on Saturday. The reaffirmation of Malaysia’s credit rating by the three major assessors backs the “government’s commitment to implement sound macroeconomic policies and fiscal reform initiatives,” he said.

The government is due to sell RM2 billion of 15-year bonds later tomorrow before 11 billion ringgit of debt matures on Wednesday. In the secondary market, the 10-year yield rose five basis points to 4.50 per cent, the highest for a benchmark of that maturity since 2008.

Malaysia’s FTSE Bursa Malaysia KLCI Index of shares fell 0.5 per cent, taking its drop this quarter to 6.3 per cent. Overseas funds have pulled a net 17.7 billion ringgit from the nation’s stocks this year, surpassing RM6.9 billion ringgit for the whole of 2014, according to a report today from MIDF Amanah Investment Bank Bhd. — Bloomberg