The loonie surged 1.28 U.S. cents to 79.55 cents US .
The American currency weakened after the central bank also signalled that there could be a rate increase later this year by no longer saying it will be "patient" in starting to raise its benchmark rate.
Analysts noted that a rate hike in June is still a possibility but the Fed won't be in a hurry to raise rates aggressively.
Meanwhile, oil prices erased early losses to move higher after six days of steep declines on supply concerns. The April contract in New York gained $1.20 to US$44.66 a barrel even as the U.S. Energy Information Administration reported a 10th straight weekly increase in crude supplies that was more than double what analysts expected.
Inventories have been steadily rising to a point where analysts are concerned that storage space could soon be at a premium, which could drive prices down even further. Prices are already down 60 per cent from the highs of last summer amid a global oversupply of crude.
May copper fell six cents to US$2.57 a pound while April gold bullion moved $3.10 higher to US$1,151.30 an ounce.