Markets were rife with speculation over possible fresh stimulus in the world's biggest economy after minutes released last week from the Federal Reserve showed US central bankers worried about slowing growth.

But that failed to spark markets into life. Hong Kong stocks ended down 0.41 percent, or 81.36 points, to 19,798.67, Sydney slipped 0.12 percent, or 5.2 points, to 4,343.7.

Shanghai ended down 1.74 percent, or 36.39 points, to 2,055.71, while Seoul was down 0.10 percent, dragged down by the sharp fall in Samsung shares.

Tokyo bucked the general trend, climbing 0.16 percent, or 14.63 points, to 9,085.39.

Shares in Samsung -- the world's biggest technology firm -- tumbled 7.5 percent, the biggest single-day percentage drop the firm has seen in nearly four years, after a California jury last week said the firm had infringed on half a dozen patents held by Apple.

Shares of other Asian smartphone makers which run Google's Android operating system, the partial target of Apple's lawsuit, were also lower.

Analysts said the fine of $1.05 billion was not a major issue for Samsung but the jury verdict raised concerns about a possible ban on some US sales when the judge in the case makes her final ruling.

Meanwhile, investors are looking ahead to Fed chairman Ben Bernanke's speech at an annual economic policy symposium to be attended by central bankers and economists later this week for further clues on possible easing.

"We have got through a quiet August," said Shane Oliver, head of investment strategy and chief economist at AMP Capital in Australia.

"And we are now coming up to a peak period in terms of events where the market patience might wear out if the policy action doesn't come out," he told Dow Jones Newswires.

Europe was also in the spotlight after Greek Prime Minister Antonis Samaras met German Chancellor Angela Merkel and French President Francois Hollande, with both leaders affirming they wanted Greece to remain in the eurozone.

But markets were braced for further tough negotiations as Merkel said she was awaiting a report by global lenders reviewing the debt-burdened country's performance on reform targets before agreeing to revisit any terms.

Merkel warned at the weekend that "every day" counts in Greece's efforts to comply with its austerity commitments and safeguard its eurozone membership.

The European common currency bought $1.2507 and 98.48 yen in Tokyo afternoon trade, compared with $1.2512 and 98.43 yen in New York late Friday.

The dollar bought 78.73 yen against 78.67 yen in US trade.

In oil markets, New York's main contract, light sweet crude for October delivery, soared $1.03 to $97.18 a barrel in the afternoon and Brent North Sea crude for delivery in October gained $1.25 to $114.84.

Gold was at $1,672.45 at 0825 GMT, compared to $1,665.90 on Friday.

In other markets:

-- Wellington was flat, rising 0.02 percent to 3,623.22

Telecom Corporation was off 3.97 percent at NZ$2.42 and Air New Zealand was down 2.19 percent to NZ$0.89.

-- Taipei fell 0.12 percent, or 9.31 points, to 7,468.22.

Hon Hai Precision gained 0.69 percent to Tw$87.5 while Formosa Plastics dropped 0.73 percent to Tw$81.6.

-- Manila was closed for a public holiday.