Standard's and Poors has lowered Spain's long term credit rating because of its weak economy and concern over bad bank loans.

S&P downgraded Spain's rating one level to AA- from AA. The rating change means it will likely cost Spain more to borrow money in the long term.

The Fitch rating agency also downgraded Spain's credit rating last week.

Spain, the fourth largest economy in the eurozone, has struggled to rise above almost two years of recession.

Meanwhile, finance ministers from the world's 20 biggest economies are meeting in Paris Friday for talks on the continuing debt crisis in Europe.

On Thursday, Fitch downgraded Swiss-based bank UBS AG and put other European and U.S. banks on negative watches amid concerns about the fragility of the global economy.

The Fitch ratings agency dropped UBS one notch from A+ to A on Thursday on the basis that Fitch no longer believes Switzerland can be the absolute guarantor of the bank's stability.

Earlier, Fitch downgraded two British banks, Lloyds Banking Group and Royal Bank of Scotland, citing the reduced likelihood of further government support.

Among the banks placed on negative watch are Barclays Bank, BNP Paribas, Credit Suisse, Deutsche Bank, Goldman Sachs, Morgan Stanley and Societe Generale.

Negative watches are warnings that the institution's business models are particularly sensitive to challenges in the financial market.