The move comes as the state seeks ways to pay for the final segments of the 142-mile project designed to link Indianapolis and Evansville. The first three sections from Evansville to Crane are open, and a fourth segment to Bloomington is under construction.
But money from the state's lease of the Indiana Toll Road, which was used to jumpstart construction of the I-69 extension, is either spent or allocated to specific projects, and the state must find a way to pay for the final two sections of the highway.
The section still to be built is expected to cost between $350 million and $500 million, the Evansville Courier & Press reported.
The state's request for information says Indiana is looking at "various public-private partnership delivery models" for the project.
INDOT spokesman Will Wingfield said that even if a contractor takes charge of the entire project, the state is still determined to bar tolls on the road.
"There is no change in our commitment that motorists will be able to drive from Indianapolis to Evansville without paying a toll," Wingfield said.
He said the state believes it would get a better price by agreeing to pay a lump sum to the contractor than by bonding out the work.