Republican Rep. Eric Turner of Cicero, who is leading the House-Senate conference committee handling the smoking ban bill, said he wouldn't support a provision added to the bill last week by the Senate that would block any new local smoking ordinances. That is one of several changes senators made in watering down the statewide restrictions.

Numerous cities and counties around the state currently have local ordinances that ban smoking in public buildings and workplaces, including restaurants and bars.

"I don't want to go down that path of trying to trump what locals have successfully done for a number of years," Turner said.

The House-approved bill would prohibit smoking in nearly all public places and businesses but give bars an 18-month exemption to the ban and continue to allow smoking at Indiana's 13 casinos, private clubs, retail tobacco stores, and cigar and hookah bars. The Senate greatly weakened the measure by cutting bars out of the proposed ban and adding new carve-outs for assorted businesses like veterans homes and nursing homes.

Casinos have argued they would see fewer gamblers if they were covered by the smoking ban — potentially threatening the some $650 million a year in tax revenue the state receives from them.

Mike Smith, president of the Casino Association of Indiana, told the conference committee that casinos worried that local governments could include them in local bans in the future if state law didn't prevent such action.

Republican Sen. Beverly Gard of Greenfield, the smoking ban bill's Senate sponsor, said she thought it was important to protect the right of cities and counties to adopt tougher smoking rules than whatever becomes state law.

Gard said that many new bars and restaurants had opened around Greenfield despite tough smoking bans in the city and Hancock County.

"It is a very family-friendly environment," she said. "No one can tell me that going smoke free is going to be bad for business because in my county and my hometown it has not been bad for business."

The negotiators expect to offer a compromise bill by the end of this week, when legislative leaders are planning to adjourn this year's session.

Republican Gov. Mitch Daniels has said he wants to see a statewide smoking ban with as few exemptions as possible, but hasn't specified what exemptions he believed were acceptable.

Anti-smoking advocates are opposing efforts to extend the bar exemption past the September 2013 deadline approved by the House. Opposition from health advocates last year to a House-approved bill that included a bar exemption without an end date contributed to its defeat in a Senate committee.

Sen. Michael Young, R-Indianapolis, offered an amendment the Senate adopted last week that would prohibit local ordinances from banning smoking at any home businesses. But Young, who was among those who opposed the bill in the Senate's 29-21 vote, said he thought smoking rules in general shouldn't be covered by state law.

"I just think this is an issue the local communities should decide," Young said.