Asian stocks mixed ahead of a key US Federal Reserve announcement

TOKYO (Reuters) - Asian stocks were mixed and the dollar marked time on Wednesday, with markets waiting for the US Federal Reserve's policy statement due later in the session for clues to when the Fed will hike interest rates.

Indonesian, Singaporean and Japanese shares fell 0.1 per cent , while Australian stocks dropped 0.5 per cent.

But Chinese shares, sitting atop multi-year highs reached on hopes of more monetary stimulus, added to gains. The Shanghai Composite Index reached its highest since May 2008, while Hong Kong's Hang Seng and South Korea's Kospi also gained.

MSCI's broadest index of Asia-Pacific shares outside Japan rose 0.4 per cent. "We expect to see a tug-of-war between the bulls and the bears," said Hue Frame, senior adviser at Atlantic Pacific Securities in Sydney.

The bulls think there won't be a rate rise in the U.S. this year while the bears see one coming "over the next few months,"he said.

The Fed statement is due at 2am Thursday Singapore time, followed 30 minutes later by a news conference with Chair Janet Yellen.

Financial markets are most interested in whether the US central bank will remove the word "patient" from its remarks on raising rates.

A number of strong US employment reports have increased wagers over the past few weeks on the Fed tightening as early as June.

The prospect of the Fed hiking rates in the summer and drawing liquidity away from the rest of the world has caused the dollar's peers to tumble and triggered tumult in emerging market equities.

US debt yields have risen, while euro zone bond yields sank to record lows as the European Central Bank implemented its quantitative easing programme. "The FOMC (Federal Open Market Committee) meeting could well produce some passing volatility but have little net impact, given that policy is sure to be on hold, while Chair Yellen should use plenty of caveats on the policy outlook in her press conference," Sean Callow, a senior currency strategist at Westpac in Sydney, wrote in a note to clients. "The removal of the word 'patient' from the statement has been so well flagged that it would be a true shock (slamming USD) if it is retained." The euro was steady at $1.0607, having crawled back from a 12-year low of US$1.0457 plumbed on Monday as dollar bulls held back before the Fed's statement.

The dollar index, which advanced to a 12-year high above the 100.00 threshold over the past week thanks largely in part to the euro tumbling on the ECB's quantitative easing scheme, stood little changed at 99.542.

The dollar was flat at 121.35 yen, having been confined to a narrow range after touching an eight-year peak of 122.04 last week.

In commodities, U.S. crude oil lingered near six-year lows as fears of a large inventory pile buildup added to the prospect of more oil entering the market if sanctions on Iran are dropped on a nuclear deal being done.

U.S. crude was down 91 cents at $42.55 a barrel, in reach of the six-year trough of $42.41 struck overnight.

Gold and copper were little changed, bracing for the Fed's statement and its potential effect on the dollar.

Spot gold was up 0.2 percent at US$1,151.10 an ounce and three-month copper on the London Metal Exchange edged 0.3 per cent higher to $5,737 a tonne.