Oil prices swing wildly in China uncertainty

Fragile financial markets are grappling with wild swings in world oil prices, unnerved by uncertainty over global supplies and the demand outlook from China.

By the close of business Monday, the price had shot up 27 percent in just three days for the US benchmark contract, West Texas Intermediate for October delivery, rebounding from six and a half year lows.

But they skidded again Tuesday when weak Chinese manufacturing data cemented concerns over demand from the world's biggest commodities consumer.

Later in the week oil prices got a boost from the European Central Bank, which on Thursday held out the prospect of yet more stimulus for the eurozone economies if needed. By the end of the week, crude oil prices were trading in London on Friday evening barely changed.

Brent North Sea crude sold at $49.95 a barrel -- down from $50.17 a week earlier. The WTI contract traded at $46.22, up from $45.22.