Moody’s rating agency on Tuesday assigned its highest mark to bonds that will be issued to cover the public investment in construction of SunTrust Park.

The agency, which assigns ratings based on the risk of default, gave its Triple-A rating on $372 million in bonds that it says Cobb County plans to issue Aug. 25. Before the rating, it was unclear when the bonds would be issued or how much the county would borrow.

Moody’s said the rating is based on the county’s “sizable and diverse economic and employment base, a sound financial position supported by conservative fiscal management and satisfactory fund balance levels, and a manageable debt burden.”

Technically, the rating was given to the Cobb-Marietta Coliseum and Exhibit Hall Authority, which will actually issue the bonds. But the debt will be mostly repaid by Cobb County taxpayers, and is guaranteed by a pledge to raise property taxes if necessary. So the county’s ability to repay the debt was the determining factor.

The county will provide $368 million toward stadium construction, but will borrow more than that to cover financing costs and initial interest payments on the debt. The county commission has authorized up to $397 million in borrowing.

An Aug. 7 amortization schedule, obtained by The Atlanta Journal-Constitution through an open records request, shows that the annual payments on the debt are likely to be $20.8 million, or about $3.2 million less than originally estimated. With those payments, the county will ultimately repay $643.7 million on the debt.

The AJC had previously reported that annual payments could be less than originally forecast.

The county also will pay $35 million for 30 years of capital maintenance, and millions more in infrastructure, public safety and other improvements.