JOIN USNew York's main contract, WTI light sweet crude for October delivery, was down five cents to USD 85.65 a barrel in morning trade, and Brent North Sea crude for November climbed 48 cents to USD 109.62.
"The downgrade of Italy by S&P upset the markets a little bit," said Nick Trevethan, senior commodities strategist at ANZ Research in Singapore. The US credit ratings firm on Monday cited economic, fiscal and political weaknesses in cutting Italy's sovereign debt rating to "A/A-1" from a "A+/A-1+".
S&P added that Italy's weak governing coalition would "limit the government's ability to respond decisively" to events.
The downgrade was more bad news for Italian Prime Minister Berlusconi and added to market nervousness already triggered by fears of a debt default by Greece.
Greece was to continue talks with the IMF and EU on Tuesday after being warned to tighten austerity measures and ramp up state asset sales to secure rescue funds and stave off bankruptcy early next month.
But heightened tensions between Athens and its bailout lenders, the European Union, European Central Bank and International Monetary Fund, have sparked concerns it could affect efforts to coordinate action to battle the crisis.
"The lack of agreement on fundamental issues is a major barrier to coordination of macroeconomic policy responses to the many threats to the global economy and financial system," said Julian Jessop, chief global economist at research house Capital Economics.