World oil prices fluctuate on Tuesday amid fears of debt crisis in Europe and the statistical data from the U.S.

Bidders disappointing news from Europe. So, before Spain formally filed a request in the Eurogroup to provide the country financial help to recapitalize its banking sector. Followed by Spain, on Monday asked for help, and Cyprus, becoming the fifth European country to ask the authorities of the EU's external financial support.

Investor sentiment and influenced by statistical data from the U.S.. So, in April, the cumulative index of house prices S & P / Case-Shiller, calculated for the 20 largest U.S. cities for the first time since autumn last year grew by 1.3%, resulting in a slower decline rate in annual terms to 1.9% with 2 and 6%. Analysts had expected the reduction rate in annual terms by 2.5%.

Oil for August delivery traded at a range of $78.36 - $79,68  a barrel on the New York Mercantile Exchange. Prices have fallen 24 percent this quarter, the biggest drop since the final three months of 2008.

Brent crude for August settlement rose 23 cents to $91.24 on the London-based ICE Futures Europe exchange. Brent’s premium to West Texas Intermediate widened for the third straight day, rising to $12.68.