COLUMBUS -- The tab for Ohio's study into how it can wring potentially billions of dollars out of the Ohio Turnpike continues to mount.

On Monday, the largely legislative Ohio Controlling Board signed off on $550,000 in special counsel contracts with outside law firms requested by Attorney General Mike DeWine to provide legal advice to the Department of Transportation for the study. ODOT will pay the tab.

Counting a $2.85 million contract for the study approved by the controlling board two weeks ago, the special counsel contracts carry the total price tag to $3.4 million.

One unbid $300,000 contract would be with the New York law firm of Allen & Overy, which DeWine spokesman Lisa Hackley said had experience with the 157-mile Indiana Toll Road project. That state entered into a 75-year lease with a Spanish-Australian consortium that generated $3.8 billion for the state.

A second $250,000 contract would be with Columbus-based Barnes & Thornburg.

The $2.85 million contract with Texas-based KPMG Corporate Finance LLC calls for it to study the 241-mile toll road and the rest stops along free interstates to see if the state can use them to generate cash for bridge and highway projects across the state.

Among the options under consideration are a long-term lease of the turnpike to a private operator, borrowing against it, transferring its operation to ODOT, and doing nothing.

Gov. John Kasich has insisted that the result of the study is not predetermined and that the recent announcement that timetables for highway projects already in the planning stages could be put off for decades because of a lack of funding was not designed to generate support for the concept. He has said that, if a deal should result, a majority of the money would be used in northern Ohio. The governor had initially suggested the state could get $3 billion in a lease agreement, but has since backed away from that number.

First Published February 28, 2012, 5:15 a.m.