AUGUSTA — State lawmakers on Wednesday amended a bill that will allow most Mainers to carry a concealed handgun without a permit, increasing the likelihood that Gov. Paul LePage will sign it.

The bill, L.D. 652, will make it voluntary for residents 21 and older to obtain a concealed handgun permit. The age requirement was added to the bill Monday, but the Senate and House both voted Wednesday to exempt active and honorably discharged military personnel from the age restriction.

The change is designed to win the signature of LePage, who told a Bangor radio station on Tuesday that he wouldn’t sign the bill if military service members 18 and older couldn’t carry handguns without a permit.

The Senate passed the amended version unanimously. The House is expected to vote on the measure Thursday.

Additional votes are required before the bill is sent to the governor.

Currently one must be at least 18 years old to obtain a concealed handgun permit. Maine will become at least the eighth state to allow the permit-less carrying of a concealed handgun if the bill becomes law.

The proposal drawn the attention of gun rights activists and advocates of gun control. The pro-gun advocates have argued that the permit requirement effectively punishes legal gun owners who want to hide their weapon under a coat or in their vehicle. Gun control activists counter that the permit system adds a layer of protection because applicants must receive gun safety training and undergo a background check by law enforcement.

The proposal has also divided the law enforcement community. The Maine State Police testified in favor of the bill, arguing that the state has not been able to overhaul its permit system. The Maine Chiefs of Police have opposed the measure, saying that the background check prevents felons and domestic violence abusers from carrying hidden handguns.

The National Rifle Association has lobbied lawmakers to support the proposal. A control group funded by former New York City Mayor Michael Bloomberg initiated paid advertisements to encourage lawmakers to defeat the bill.

The bill would not eliminate the permit system, but would make it voluntary. State police now handle permit applications for about 300 Maine towns, but many local police departments or other municipal officials process the permit applications on their own. The process includes a background check for a criminal record, similar to the check conducted by the federal government for felony convictions when someone buys a gun from a retailer. But police have broad discretion and can deny a permit for relatively minor offenses, such as reckless conduct or operating under the influence.

The Maine State Police say 36,000 concealed handgun permits, including 12,000 for non-residents, have been issued by the state. The total number of permits is likely much higher because they are also issued by local police and there is no centralized registry.

This story was updated at 9:28 a.m. on Thursday, June 4, 2015 to correct the age at which one can obtain a concealed handgun permit in Maine.