Tuesday's agreement by international lenders to cut Greece's debt offered relief, but skepticism over the lack of details on how Athens will carry out budget reforms capped a rise in European shares and the euro.
U.S. stocks slid overnight after Senate Majority Leader Harry Reid, D-Nev., voiced disappointment over little progress in dealing with an approaching "fiscal cliff."
MSCI's broadest index of Asia-Pacific shares outside Japan inched down 0.2 percent, retreating from Tuesday's nearly three-week highs, Reuters reported.
Australian shares fell 0.4 percent, easing from two-week highs. Government data on Wednesday showed a slowing in investment in the resource sector, the main driver of Australian growth, as costs rose and commodity prices decline, driven by a drop in Chinese demand.
South Korean shares opened 0.5 percent lower.
The euro was down 0.1 percent to $1.2937, slipping from a peak of $1.3010 hit on the Greece news on Tuesday, its highest level since Oct. 31.
Japan's Nikkei opened down 0.5 percent, after closing at a seven-month high. The average has risen 8.8 percent over the past two weeks since the government announced a Dec. 16 election. Japan's main opposition party is forecast to win, and investors expect it will force the Bank of Japan into aggressive easing.