The euro as fallen against the US dollar as a European Union (EU) summit opened on how to address the eurozone's long-running sovereign debt crisis.
"EU leaders arrived for a Brussels summit on Thursday more openly divided than at any time since the euro crisis began, with Germany's Chancellor Angela Merkel showing no sign of relenting in her refusal to back other countries' debts," said Robert Brusca at FAO Economics.
The euro was traded at $US1.2442 around 2100 GMT (0700 Friday AEST), slipping from $US1.2467 at the same time Wednesday.
The European currency also weakened against the yen, to 98.85 from 99.38 yen late Wednesday, as did the dollar, dipping to 79.45 yen from 79.71.
"Markets are expecting little in the way of significant progress, although Chancellor Merkel indicated that a growth package is in the works with details to follow shortly," said Jason Ball, a Wells Fargo Bank analyst.
EU leaders battled Thursday to restore faith in the euro, shared by the 17 member nations of the eurozone.
The EU chiefs huddled for a two-day summit among market jitters and pressure from global leaders to find a solution to prevent the eurozone debt crisis from dragging down the world economy.
The dollar firmed against the Swiss currency, to 0.9650 francs from 0.9631 francs late Wednesday.
The greenback gained against the British pound, which fell to $US1.5515 from $US1.5563.