Returning to a national currency after more than a decade of using the euro and having its money managed by the ECB would catapult Greece into a financial, legal and political no-man's land.
The dollar pared gains after an unexpectedly weak regional manufacturing report in the U.S. raised some expectations that the Fed may ease monetary policy again. The euro traded around $1.27.
The China Financial Futures Exchange this week sealed agreements with four Western exchange operators, aiming to tap the expertise of established markets following a surge in trading volume.
Greece mandated a senior judge to form a government as caretaker prime minister ahead of new elections next month, after political parties failed to agree on a political or technocratic heavyweight for the job.
Asian markets ended mixed, stabilizing after the previous day's heavy selling as worries over Europe subsided for the moment; the Shanghai Composite gained 1.4%.
India's Piramal Healthcare plans to acquire health-information manager Decision Resources of the U.S. for about $635 million, and Piramal's chairman assailed "an antibusiness feeling" in India.
The dollar was in demand as investors worried about the next installment of the euro-zone debt crisis fled currencies and markets deemed as relatively risky and sought refuge in the greenback and German bunds.
A Japanese ruling-party heavyweight said the government must intervene in the currency markets if the yen's rise accelerates sharply, adding to the level of jawboning aimed at controlling the currency's moves and its impact on the economy.
The dollar inched higher versus major rivals, though the day's trading was punctuated by periods of sharp reversals. The euro has fallen against the dollar in 12 of the past 13 days.