Both crude benchmarks had climbed on Tuesday after financial markets shook off some of the shock of last week's referendum in the UK in which a majority of voters elected to exit the EU, triggering turmoil across markets and regions.

"The risk-on tone should see commodities continue to push higher," ANZ Bank said on Wednesday.

"Oil led the (commodities) sector as the shock of the UK voting to leave the EU wore off. Oil gains were solidified by news that the decline in Venezuela's oil output appears to be accelerating, while a strike in Norway also looked like it would impact production," it added.

Prices were also supported by supply fundamentals, as a looming strike by Norwegian oil and gas field workers threatened to cut output from the biggest North Sea producer.

Reports that oil producers and refiners in crisis-struck Venezuela were struggling to keep output up due to power outages and equipment shortages also supported prices, traders said.

Additionally, the American Petroleum Institute indicated in a preliminary report on Tuesday that crude inventories could have fallen nearly 4 million barrels for the week to 24 June, some two-thirds more than the 2.4 million barrels expected by analysts.

The US Energy Information Administration will issue official stockpile data on Wednesday.