Moody's has raised its outlook for Spain's banking system to positive from stable, as robust economic growth and disposals of troubled assets help banks bolster their asset quality. In the rating agency's view, other fundamental factors such as capital, funding and liquidity levels and profitability will remain stable.

"The stock of non-performing loans at Spanish banks will continue to decline on the back of a growing economy," said Alberto Postigo, a Vice President and Senior Credit Officer, at Moody's. "Asset quality will be further improved by the large sales of troubled assets on which several Spanish banks are embarking."