The Illinois Restaurant Association (IRA) on Thursday announced its support for a bill that seeks to make Illinois the 14th state to legalize gay marriage.

“As owners of small and large businesses, our members know the importance of treating all customers equally,” said IRA President Sam Toia in an emailed statement. “It's the right thing to do – and it's good for business.”

The group called on the Illinois House to approve a marriage bill, which stalled in the House after clearing the Senate on Valentine's Day, when lawmakers reconvene later this month.

Toia pointed to a study by the Williams Institute at the UCLA School of Law showing that marriage equality would generate up to $103 million in spending in the state within the first three years of legalization.

“As a businessman, I worry that Illinois is falling behind,” Toia said.

Illinois is one of four states where gay and lesbian couples are recognized with civil unions, not marriage – the other three are New Jersey, Hawaii and Colorado. Following a Supreme Court decision in June which gutted much of the Defense of Marriage Act (DOMA), the federal government started recognizing the unions of gay couples in a marriage, leaving couples in a civil union at a distinct disadvantage in terms of benefits.

(Related: New Jersey judge won't delay order legalizing gay marriage.)