Rating agency Moody's Investor Service on Wednesday put Spain's Aa1 sovereign credit rating on review for a possible downgrade, citing concerns over the country's mounting debt and its funding needs in 2011.

It also cited worries over the central government's control of local authorities in achieving structural improvements in Spain's general finances.

Moody's believes that the above-mentioned downside risks warrant putting Spain's rating under review for downgrade, said Kathrin Muehlbronner, Moody's lead analyst for Spain.

However, Moody's also wants to stress that it continues to view Spain as a much stronger credit than other stressed euro zone countries. This is reflected in the significantly higher rating for the Spanish sovereign. Moody's review will therefore most likely conclude that Spain's rating will remain in the Aa range.

On Tuesday, Standard & Poor's cut its outlook on Belgium on concerns over the general fiscal outlook.

(Reporting by Kazunori Takada; Editing Neil Fullick)