Oil slid below $68 this afternoon, the fourth day in a row that prices fell, reflecting increased petrol output in the US.
A fresh attack on a Nigerian pipeline provided some support, though analysts played down the impact of a 6.5% drop in Chinese stocks that sent ripples through other Asian and European markets.
Brent North Sea crude for July delivery slipped 66 cents to $67.47 a barrel in electronic deals. It had shed $1.58 on Tuesday.
New York's main oil futures contract, light sweet crude for delivery in July, firmed 15 cents to $63.30 a barrel in floor trading. On Tuesday the contract dived $2.05.
Relatively low petrol stocks in top consumer the United States at the start of peak summer demand helped drive Brent crude oil to a nine-month high above $71 last week.
The next snapshot of oil demand and stocks in the United States is due tomorrow.
