INDOT says in a news release that the state expects to receive between $80 million and $100 million in federal transportation funding.
INDOT is hosting three public meetings in mid-September to show new refinements to the Section 6 plan.
The state hoped to take control of Section 5 construction by the end of July.
INDOT will take over construction and maintenance of the road by the end of July.
The state says the 21-mile stretch of interstate won't be complete until August 2018.
The project covers a 14-mile section of I-65 between U.S. 50 in Seymour and Indiana 58 near Columbus.
An infrastructure bill lawmakers approved this session funnels hundreds of millions of dollars into the state’s roads and bridges.
The Indiana Department of Transportation is surveying wetlands, streams and other environmental features to further refine the I-69 expansion plan.
The first hearing is tonight at Perry Meridian High School on Indianapolis' south side.
The letter says the Indiana Finance Authority, Isolux Corsan, and I-69 Development Partners are negotiating to come up with a "Memorandum of Understanding."