Chinese rating agency Dagong Global Credit Rating said on Wednesday it has downgraded Italy's sovereign rating to BBB from A-minus, citing Italy's gloomy economic growth prospects.

The Beijing-based Dagong also maintained its "negative" outlook on Italy.

"Italy's bond yields will continue to rise due to a worsening economic and financial environment, and that will give a heavy blow to Italy that is relying on external borrowing," Dagong said.

Moody's cut Italy's sovereign debt rating to A2 from Aa2 two months ago, and Standard and Poor's rates Italy's long-term sovereign debt at A. Both maintained a negative outlook on Italian debt.

Dagong, little known outside China, is the only Chinese agency that provides sovereign ratings for about 50 countries. The company has said it aims to break monopoly of western rating agencies.

Last month, Belarus signed a deal with Dagong, hoping for a more generous assessment of its sovereign debt after being downgraded repeatedly by western rating agencies.

In August, Dagong lowered its rating on the United States to several notches below its top rating, putting it on par for creditworthiness with countries such as Spain, Estonia and South Africa.