It will cost Gwinnett County slightly more than originally projected to finance the new baseball stadium it is building for the top minor-league affiliate of the Atlanta Braves.

Bonds sold to provide $33 million in funding for the project will carry a fixed 6.25 percent interest rate, up from the 5.95 percent rate county officials had projected in the financing models made available to the public last month.

The rate changed because of market conditions, Finance Director Lisa Johnsa said. Buyers bid on bonds and the seller accepts the best available rate.

Johnsa said Tuesday that she did not have immediate access to documents detailing the interest payments and could not say how much the change in rates would increase annual debt service payments on the project.

"It's a few basis points higher than we were hoping for. It's still something we can manage," she said.

One basis point represents one hundredth of a percentage point.

Initial payments will be lower than those in later years because the county has opted to defer making principal payments on the bonds for five years, Johnsa said.

The county opted for the delayed principal payments because it must begin paying on the bonds in January, but the stadium will not have its first full year of operations until 2010, she said. It is scheduled to open in spring 2009.

The county plans to repay the debt on the stadium in 30 years through rent on the stadium, ticket surcharges, a share of parking revenues, a share of stadium naming rights and money from a new tax on vehicle rentals. It is paying $12 million up front for the land and part of construction costs on the $45 million stadium.

On Tuesday the County Commission agreed to authorize Chairman Charles Bannister to sign documents necessary to close on the bond sale, which is scheduled for April 1.

Those documents include the intergovernmental agreement between Gwinnett County and the county's development authority, which will issue the bonds, and the operating and maintenance agreement between the county and the Gwinnett Convention and Visitors Bureau, which will manage the stadium.

Bond buyers demand such documents much as mortgage companies require various documents from home buyers at closing, Johnsa said.