SOUTH PORTLAND — The city received a AAA bond rating from Moody's Analytics, making the city the highest-rated municipality in the state, according to a city official.

Finance Director Greg L'Heureux said the Moody's rating – the highest awarded by the firm – and a AA-plus rating from Standard & Poor's have already benefited the city through a lower interest rate on a $30 million bond for the renovation at South Portland High School.

That 10-year bond comes with an effective interest rate of about 2.52 percent, L'Heureux said, about 0.2 percent lower than it would have been if South Portland had received a less favorable rating from Moody's.

Bond ratings are a measure of a municipality's ability to pay down debt. South Portland has maintained its AAA/AA-plus rating for about two years. Nearby Portland has a AA1 rating from Moody's (one step below South Portland) and a AA rating from S&P.