The Korean won fell a quarter of a percent on Thursday, and the Taiwan dollar and Philippine peso also weakened as retreating regional stock markets held some of the regionals back after a broad US dollar rally lost momentum.
The dollar was hit by data on Wednesday showing a slowdown in the US services sector and on reports the Venezuelan central bank may be diversifying out of dollar assets.
But the yen's rally towards 113.75/80, further away from 16-month lows struck this week, failed to inspire all the regionals uniformly.
The North Asians were weak, while the Singapore dollar and the Thai baht rallied.
The Indonesian rupiah touched a 7-week peak in early trading, boosted by foreign investment inflows and news of the government's $1.5 billion bond being heavily oversubscribed. But the Jakarta stock exchange's retreat caused the rupiah to give up some of its gains.
The won hit 1,042 a dollar, down from an intra-day high near 1,037 as Seoul's share market fell and foreigners sold Korean stocks for a 10th session.
Callum Henderson, currency strategist with Standard Chartered Bank, said in a note to clients he would sell the won and buy yen, because the won's strength this year had hurt Korea's export competitiveness, while the Japanese economy was on a self-sustaining recovery path.
Bhanu Baweja, currency strategist with UBS, said although the won could appreciate against the dollar, it would not do so in trade-weighted terms.
"I can't see the won going higher against the euro or yen," Baweja said.
The won faces headwinds from a vulnerable economy, with consumption likely to remain sluggish and the government expected to continue to thwart won gains, he said.
Though the rupiah stalled after hitting a 7-week peak of 9,970 a dollar, traders said offshore investors, impressed with policy measures including rises in yields and domestic fuel prices, pumped money into Indonesia's stock and bond markets.
The rupiah firmed past the 10,000 mark for the first time in more than 3 weeks and extended its gains this week to nearly five percent. It subsequently pared some gains to settle around 10,050/10,060 per dollar.
"The yield is now very attractive. Foreigners are buying rupiah bonds and stocks," one Singapore-based trader said.
Indonesia's government announced a larger-than-anticipated rise in domestic fuel prices last week, including a doubling of gasoline prices and a trebling of the cost of household kerosene from Saturday. Those moves would help reduce imports of expensive oil and the government's subsidy bill.
Higher fuel prices are expected to feed into inflation which is already running at an annual rate above 9 percent.
This week, Bank Indonesia raised the yield on benchmark one-month bonds to 11 percent, taking total rate rises since August to 250 basis points.
Henderson favoured buying the rupiah. "This currency benefits from favourable positional risk and a current account surplus. In addition, the Indonesian authorities have done much to repair policy credibility," he said.
"The combination of these moves should help slow the economy, reduce oil-related dollar demand and provide further support for the external balance."