Oil prices have risen about one per cent to three-year highs, pushing the global Brent benchmark past $USUS70 a barrel, on further signs of tightening supply in the United States and expectations that OPEC's output cuts would underpin the market.

Oil prices have risen about one per cent to three-year highs, pushing the global Brent benchmark past $USUS70 a barrel, on further signs of tightening supply in the United States and expectations that OPEC's output cuts would underpin the market.