An oversupply of oil from new sources across North America is keeping crude prices depressed, the International Energy Agency said in a report Tuesday.

The Paris-based IEA said Canadian oilsands oil and conventional crude from other sources are having a "transformative" effect on the price of oil across the globe.

The impact on oil prices of those new sources of crude will be as significant over the next five years as China's booming demand was over the past 15, the IEA said.

"North America has set off a supply shock that is sending ripples throughout the world," the group's executive director Maria van der Hoeven said.

The IEA expects the flow of crude oil out of North America to grow by 3.9 million barrels per day between 2012 and 2018. That's almost half as much as the total amount the agency expects global output to expand by, 8.4 million barrels per day.

OPEC output also higher

Currently, the world uses about 90.6 million barrels a day of oil. Within six years, that's set to increase to 96.7 million barrels a day, but the IEA's forecast still sees supply outstripping that, and that relative oversupply will likely keep prices lower, the group says.

Even OPEC, which works hard to keep oil prices above a certain level by limiting supply, finds itself putting out more oil than it means to at the moment.

A report Monday shows oil output from OPEC nations increased by 250,000 barrrels per day in April, putting the group at 30.5 million barrels a day. That's at least a half-million barrels higher than OPEC's current target of 30 million barrels a day.

In New York, the price of the dominant crude oil contract lost 45 cents to trade at $94.72 US on Tuesday. The price of oil had increased on Monday after U.S. data showed retail spending rebounded last month.