Brent North Sea crude for delivery in November gained 90 cents to $109.07 a barrel approaching midday trade in London.
New York's main contract, light sweet crude for November climbed 53 cents to $88.67 a barrel.
Data from the United States released late Wednesday added to an upbeat outlook for the world's largest economy and oil consumer, analysts at IG Markets trading group said in a note to clients.
"This week traders have seen more positive numbers out of the world's largest economy that suggest it could be turning a corner at last," they said.
The note cited an improvement in the forward-looking Purchasing Managers' Index for the US services sector in September, which followed a rise in the country's manufacturing activity.
The US private sector also added 162,000 jobs in September, according to a closely-watched survey.
However, analysts said prices were being weighed down by worries over Spain and a slowing Chinese economy.
"This past week, European attention has been focused on Spain's problems," said Sanjeev Gupta, who heads the Asia-Pacific oil and gas practice at Ernst and Young.
Traders were watching Spain for hints on whether it would ask for a eurozone bailout soon, after Catalonia president Artur Mas on Wednesday said the move was unavoidable and Madrid should ask for it without a long delay.
His comments came after Spanish Prime Minister Mariano Rajoy refused to say whether the eurozone's fourth largest economy needs rescuing, insisting instead on the need to study the matter.
Gupta added that in Asia markets were worried about signs of an economic slowdown in China, the world's biggest energy consumer.
