By Brendan O'Brien

MILWAUKEE (Reuters) - Wisconsin lawmakers voted on Tuesday to repeal the state's 48-hour waiting period on handgun purchases, a measure supporters say will make transactions more convenient and opponents contend will lead to increased violence.

The Republican-controlled legislature also approved a bill that allows off-duty and retired law enforcement officers to carry concealed guns on school grounds.

Both bills have been sent to Governor Scott Walker, a potential Republican candidate for president in 2016. Walker plans to sign the bill repealing the 48-hour waiting period and will evaluate the school-carry bill when he receives it, the governor's office said on Tuesday.

Representative Romaine Quinn, a Republican supporter of the measure, said the waiting-period repeal bill simply allowed law-abiding citizens to take a gun home the day they purchase it.

"This is not about putting guns in the hands of criminals," Quinn said before the Assembly approved the bill on a voice vote. The state Senate approved the measure in April.

The state's current 40-year-old law requires a firearm dealer to wait 48 hours after a Wisconsin Department of Justice background check is completed before selling a handgun to a buyer.

That waiting period "could mean the difference between life and death," argued Democratic state Representative Lisa Subeck, saying the waiting period helped prevent suicide and domestic violence.

Also on Tuesday, both the Assembly and state Senate approved a bill to allow off-duty and retired law enforcement officers to carry concealed guns on school grounds.

Wisconsin state law currently prohibits the carrying of a firearm within 1,000 feet of a school.

(Reporting by Brendan O'Brien in Milwaukee; Editing by Peter Cooney)