* Asian markets up; Europe may open higher
* Gold extends decline; Nikkei up 1.8 pct, MSCI Asia ex-Japan up 0.3 pct
* Currency markets subdued, eyes on Bernanke speech Friday (Updates prices)
By Ian Chua
SYDNEY, Aug 25 (Reuters) - Asian shares rose on Thursday, pointing to a positive open in Europe, but caution prevailed as investors awaited the outcome of a central bank symposium in Jackson Hole on Friday.
Following solid gains on Wall Street, Japan's Nikkei share average advanced 1.5 percent, while stocks elsewhere in Asia as measured by MSCI added 0.4 percent.
Financial bookmakers expect European shares to open higher as well, although the opening gain may be less than 0.5 percent.
Gold extended its spectacular decline, after a wave of profit-taking triggered the biggest daily drop in futures since 1980, while currencies marked time ahead of a speech United States Federal Reserve Chairman Ben Bernanke on Friday.
"If there is no form of stimulus announced on Friday markets may be susceptible to sharp declines given how much weak data has been ignored over the last couple of days," said Jonathan Sudaria, a night dealer at London Capital Group.
"Basically people are covering short positions before Jackson Hole. I'm sure he will comment on the possibility of easing but I doubt he can explicitly indicate QE3," said Hideyuki Ishiguro, assistant manager of investment strategy at Okasan Securities.
In the U.S., Apple shares tumbled as much as 7 percent in
after-hours trading after the shock resignation of its chief
executive officer Steve Jobs, knocking Nasdaq futures
Spot gold slipped to $1,732 an ounce, taking losses to some $180 since it hit a record high of $1,911.46 earlier in the week.
The fall came after COMEX futures for the precious metal fell over $100 on Wednesday, the biggest one-day drop since 1980 and one of the steepest on record.
Gold faced renewed pressure on Thursday after CME Group raised trading margins on bullion futures by about 27 percent, the biggest hike in more than two and a half years and the second increase in a month.
Gold prices have jumped $400 since July as worries about a global recession sent investors scrambling for the safe-haven asset. The intensity of the move prompted some analysts to call for gold investors to take money off the table.
Traders attributed the unwinding of long positions as the main factor driving down gold as well as U.S. Treasuries, rather than a return of risk appetite.
"I don't think market players are all that bullish about the outlook for the global economy," said Makoto Noji, senior bond and currency strategist for SMBC Nikko Securities in Tokyo.
"If economic conditions don't show much improvement as we enter September and October, I think U.S. authorities will face pressure again to adopt additional economic stimulus measures and the dollar could come under pressure, especially against the yen," Noji said.
In the currency markets, the euro traded around $1.4406 , down from this week's peak near $1.4500. But it remained in the middle of a prevailing $1.4300-$1.4500 range.
This saw the dollar index edge back above 74.000, still stuck in slim range roughly between 73.400 and 74.400.
Against the yen, the dollar drifted up to 77.02 ., putting more distance from an all-time low around 75.94 plumbed Friday.
Copper inched up 0.2 percent to $8,892 per tonne,
while U.S. crude