Providence — Federal highway regulators have told state officials that if the Pawtucket Red Sox build a stadium on land that was supposed to be a park, the land will have to be sold at fair market value first, a requirement that could add millions to the bottom line.

The state Department of Transportation wrote to the Federal Highway Administration at the request of the I-195 Commission, which asked about the land's requirements.

The federal agency responded Aug. 13, telling the transportation department the land given to the commission for free has a stipulation that it remains open space.

Any change in use would require the land to be first returned to the transportation department and resold at fair market value.

The team's original plan eyes riverfront land designated as open space.