Asian shares and the euro drifted down Thursday as investors fretted over whether European leaders can agree a plan to tackle the euro zone's two-year-old debt crisis at a make-or-break summit this week.

A report that the G20 was preparing a $600 billion (512 billion pound) lending facility for the International Monetary Fund (IMF) to help Europe gave a late lift to U.S. stocks and briefly boosted the euro, but the effect faded after it was denied by G20 and IMF officials.

With big set-piece events looming -- the European Central Bank's final monetary policy meeting of the year Thursday and the EU summit Friday -- investors were unwilling to commit new funds. Riskier assets such as commodities lost ground.

MSCI's broadest index of Asia Pacific shares outside Japan <.MIAPJ0000PUS> eased 0.1 percent, while Tokyo's Nikkei share average <.N225> lost 0.7 percent. S&P 500 futures were flat, after small gains on Wall Street <.DJI> <.SPX> on Wednesday. <.N>

The euro slipped a little to just below $1.34, within the tight $1.3332/3486 range of the past week.

U.S. crude eased around 0.1 percent to $100.41 a barrel and gold fell around $2.50 to below $1,739 an ounce.

(Editing by Yoko Nishikawa)