The euro was trading at $1.4706 around 1730 GMT, up from $1.4666 an hour earlier, just before the Fed's policy-setting panel announced its decision to hold its key interest rate at 0-0.25 percent, as widely expected on financial markets.

The Federal Open Market Committee also signalled it would maintain its $600 billion stimulus program through June as originally planned.

But it left open the possibility of keeping bond investments under the program steady at $600 billion, rather than let them decline as the assets mature.

The Fed's ultra-low rates and accommodating support of the recovery have weighed on the dollar as it faces other key currencies with higher returns, such as the euro which is underpinned by the European Central Bank's tightening monetary policy.

The euro fetched $1.4636 in late New York trade Tuesday, when it also jumped above $1.47 for the first time in 16 months.

All eyes in the financial markets were turned toward the upcoming historic news conference by Fed chairman Ben Bernanke at 1815 GMT, the first for him or for any Fed chief after an FOMC meeting.