Most Asian markets edged up Wednesday but early gains from an oil rally tapered off, with worries about the global economy and the upcoming earnings season keeping traders on edge.
The return of nervousness to global markets put further pressure on the dollar, which was sitting at 17-month lows against the yen.
However, despite the adverse impact on Japan's exporters, Prime Minister Shinzo Abe has ruled out intervening to reverse the yen's rise.
After a confident rebound in March, analysts suggest dealers from Asia to the Americas may be concerned that the advances -- which followed January and February's bloodbath -- were a little overdone.
Oil, which last month rallied above $40 for the first time this year, is back on the agenda as market-watchers await a crucial meeting of producers aimed at addressing a supply glut and plunging prices.
Prices soared in March after the talks were arranged by oil giants Saudi Arabia and Russia in a bid to end a slump that had battered global markets.
Those hopes were dealt a blow on Friday, when Riyadh said it would not take part without agreement from Iran and other major suppliers.
But the two main crude contracts picked up Wednesday after Kuwait said it still thought the April 17 meeting in Doha could produce a deal, even without the inclusion of Iran.
"Oil producers have no option but to freeze their production as oil prices are low and hurting everyone," Kuwait's OPEC governor Nawal al-Fezaia said. "All early signs before the meeting point to this conclusion."
In afternoon trade, West Texas Intermediate was up three percent at $36.95 and Brent added 2.1 percent to $38.66.
- Volatile oil -
"Oil is going to be very volatile in the lead-up to the meeting," said Angus Nicholson, an analyst at IG Ltd. in Melbourne. "It's so uncertain as to whether a deal is going to be reached," he told Bloomberg News.
The gains in oil lifted energy firms in the morning but they mostly ran out of steam later in the day, with Hong Kong-listed PetroChina down and CNOOC flat. Japan's JX Holdings and Inpex also closed in the red.
However, in Sydney, Woodside Petroleum and BHP Billiton stayed the course to end higher.
Broader stock markets were mostly up but off their earlier highs.
Tokyo ended down 0.1 percent, retreating for a seventh straight day as a strong yen overshadowed a surge in utilities after a court ruled the country's two operating nuclear reactors can remain online.
The Nikkei has lost more than eight percent since its close on Monday last week.
Hong Kong ended up 0.2 percent, while Shanghai broke a four-day rally to close 0.1 percent lower. Taipei shed 1.7 percent as dealers there returned from a two-day holiday.
Sydney and Seoul each added 0.4 percent while Singapore was up 0.3 percent.
In early European trade London and Frankfurt each climbed 0.2 percent and Paris added 0.3 percent.
The dollar bought 110.37 yen, a level not seen since October 2014, after falling through the 110 mark in New York at one point.
But in an interview with the Wall Street Journal Abe said the government would not step in, which could risk a currency war.
"Whatever the circumstances, we must definitely avoid competitive devaluation, and I think we should refrain from arbitrary intervention in currency markets," he said.
Uncertainty on world markets and the prospect of no rise in US interest rates until late this year have sent dealers scurrying for the yen, considered a safe bet in times of turmoil.
- Key figures around 0830 GMT -
Tokyo - Nikkei 225: DOWN 0.1 percent at 15,715.36 (close)
Shanghai - Composite: DOWN 0.1 percent at 3,050.59 (close)
Hong Kong - Hang Seng: UP 0.2 percent at 20,206.67 (close)
London - FTSE 100: UP 0.2 percent at 6,105.90
Euro/dollar: DOWN at $1.1379 from $1.1384 on Tuesday
Dollar/yen: UP at 110.37 yen from 110.28 yen
New York - Dow: DOWN 0.8 percent at 17,603.32 (close)