Stocks were weaker in Europe and the US. Germany's DAX 30 fell 0.2 per cent and France's CAC 40 was down 0.8 per cent.
On Wall Street the Dow Jones Industrial Average was recently down 0.5 per cent. Macy's Inc was among decliners, falling 3.6 per cent as retailers extended Black Friday discounting.
Thanksgiving weekend sales rise 13 per cent to US$59.1 billion, according to the National Retail Federation. That's shy of the 16 per cent gain in the same period last year.
The other leg of this week's double is the resumption of talks between President Barack Obama and Republicans on the fiscal cliff. The Congress is seeking a budget deal to avoid $607 billion of automatic tax increases and spending cuts from kicking in on Jan. 1 - just 36 days away. Failure to act could drive the world's biggest economy back into recession and result in a spiralling jobless rate.
Talks over Greece and the fiscal cliff are "just enough reason at this point in time to take risk off the table and wait for more insight and clarity," Peter Sorrentino of Huntington Asset Advisors in Cincinnati told Bloomberg.
The British pound found strength in the surprise announcement that Bank of Canada chief Mark Carney has been tapped for the top job at the Bank of England.
"I think the markets will interpret this as perhaps ushering in a rather tighter monetary stance from the Bank of England," Stephen Lewis, an analyst at Monument Securities, told Reuters.
The pound strengthened to rose to $1.6016 against the dollar after Carney's appointment was announced, from about $1.6003.
In other appointments, Elisse Walter, former senior executive vice president at the US Financial Industry Regulatory Authority, has been named as next chairman of the US Securities and Exchange Commission as incumbent Mary Schapiro is to step down on Dec. 14 after being at the helm since 2009.
Schapiro climbed into a hornet's nest as it faced fallout from the Bernard Madoff fraud and for its oversight of Lehman Brothers.
Meantime, New York City mayor Michael Bloomberg is seeking US$9.8 billion in federal funds to help pay for repairs from damage caused by Hurricane Sandy, whose total costs run to US$19 billion.
And Egyptian President Mohamed Mursi has been in talks with senior judges after violent protests over his move to increase his powers in the Middle Eastern nation.