Moody's Investor Service downgraded Hamilton County's outstanding stadium sales tax revenue bonds, but the ratings agency retained the bonds' investment grade status.

Moody's dropped the bonds to "A2" from "A1," which is upper-medium grade and indicates low credit risk.

The county has about $558.5 million of parity sales tax revenue debt outstanding, according to the report.

The bonds are secured by a gross revenue pledge of a half percent countywide sales tax approved by voters in 1996. The original bond proceeds were used to finance construction and improvements of Great American Ball Park and Paul Brown Stadium.

One of the reasons Moody's dropped the rating because of stagnant growth trends in pledged revenue, made worse by substantial declines during the recession.

Moody's outlook on the county's sales tax revenue rating is stable.