PALMETTO -- A plan to restructure debt at Port Manatee through county guarantees has upgraded the authority's bond ratings.

Fitch last week assigned an improved "AA+" rating of the port's $37 million in bonds following a review as part of the refinance process, which will save millions of dollars through lower interest, according to public records.

The upgrade was primarily driven by the strength of guarantees from Manatee County, which will secure the debt from default with any revenues available through an inter-local agreement between the county and the Port Authority.

The financial evaluation by Fitch also assigned a "AAA" rating to the county's $9.6 million general obligation bonds and an "AA+" rating to the $111.9 million non-ad valorem bonds.

"Ports are notoriously hard to get rated," said Chips Shore, Manatee County clerk of circuit court and comptroller. "The other thing they did was approve the general obligation loan for the county, which is big, because other counties are having their bonds downgraded."

The port is expected to sell its bonds the week of Oct. 22, and a price will be negotiated with interested firms, ultimately leading to a better interest rate and operational savings, Shore said.

The Fitch rating also improves the port's credibility so less county backing will be required on future borrowing.

"We hope the port one day will be able to stand on its own," Shore said.

The Fitch report praised the efforts of Manatee County to keep a stable financial picture through choppy economic times.

The county's primary source of revenues have largely rebounded since the recession muscled four consecutive years of property

devaluations -- shrinking the collected tax pot.

Under the present spending plan, balances are expected to remain well above the policy minimum of 20 percent to expenditures. Another $45 million in operating draw-downs are projected in the next four years, according to Fitch.

Those factors slimmed the county's financial risk, and ultimately now, that of the port, leading to the improved ratings.

"The county's exceptional credit profile includes strong financial reserves buttressed by proactive management, a modest and rapidly amortized debt loan, and a diverse and strengthening economy," Fitch stated in its review.

Josh Salman, Herald business writer, can be reached at 941-745-7095. Follow him on Twitter @JoshSalman