The U.S. dollar fell against major currencies on Tuesday, hitting a six-month low against the euro, as Treasury yields retreated and the timing of the Federal Reserve's reduction of its stimulus efforts remained uncertain.

The U.S. currency fell against the yen and the Swiss franc, with investors choosing these safe-haven currencies as global shares retreated and emerging market currencies endured another wave of selling.

U.S. 10-year bond yields dropped after hitting two-year highs in the previous session on anticipation of Fed tapering of its bond-buying. The release of its July meeting minutes on Wednesday could provide clues to whether the central bank will pare back those purchases in September.

"Fed uncertainty, mixed messages on the U.S. economy and U.S. interest rates below recent peaks gnawed at the greenback," said Joe Manimbo, senior market analyst at Western Union Business Solutions in Washington, D.C.

"Minutes that suggest the economy is not quite in 'taper shape' would leave the greenback vulnerable."

The dollar index, a measure of the dollar's value against a basket of six currencies, fell 0.4 percent to 80.865 .DXY.

In thin trade, the euro rose 0.7 percent to $1.3426 as the 10-year yield premium that U.S. Treasuries offer over German Bunds narrowed. The euro had reached a session peak of $1.3452, according to Reuters data, its highest since February 14.

Mankash Jain, head of FX and investment management at Solo Capital, a London-based hedge fund, said volumes are nearly 50 percent lower than in April, so price moves can get exaggerated.

"To us, any dip in the dollar offers a buying opportunity, especially against the yen, the Swiss franc, the euro and the pound."

Many investors believe the Fed remains likely to be the first among major central banks to unwind its liquidity program. That, combined with an improving U.S. economy and rising risk aversion, should favor the dollar.

The dollar fell 0.4 percent to 97.13 yen. Weakness in global stocks along with a selloff in emerging market currencies on fears of a Fed move next month have supported the Japanese currency.

The dollar also slid 0.7 percent to 0.9174 Swiss franc.

"Investors are risk-averse going into the Fed minutes and until they get a clear direction we are likely to see these conditions prevail," said Simon Derrick, head of currency research at Bank of New York Mellon.

Subdued risk appetite hurt higher-yielding, growth-linked currencies. The Australian dollar fell 0.3 percent to $0.9081.

The New Zealand dollar slid 1.1 percent to $0.7979 after the central bank there announced home lending restrictions and said the currency was overvalued.

Emerging market currencies tumbled as jitters about the future of U.S. stimulus have badly affected the emerging assets of Asia. Investors fear an end to cheap money and an improvement in the performance of advanced economies will reverse a flow of much-needed capital.

The Indian rupee fell to a fresh record low, forcing the central bank to intervene in the market while the Indonesian rupiah hit fresh four-year lows.