The Illinois Gaming Board turned down a request from casino operators to allow casinos in the state to remain open 24 hours a day.

The casinos asked for longer hours to offset a steep decline in gambling revenue recently that the casinos attribute to a weak economy and a new state law that prohibits smoking in public places. The state’s nine casinos are required to close for at least two hours a day, and some opt to close longer.

Casinos’ hours are set by the board’s administrative staff. When the casinos petitioned to operate around the clock, Administrator Mark Ostrowski asked for direction from the five-member gaming board.

Chairman Aaron Jaffe said gambling opponents who registered intense opposition to the idea during a public hearing April 8 persuaded board members to leave the hours unchanged.

Religious leaders, addiction counselors and others opposed to casino gambling argued that around-the-clock casinos would cater to gambling addicts. They predicted that 24-hour casinos would make it easier for gamblers to engage in binges where they forsake food and sleep for days while they try to recover huge losses.

“They made a better case than the casino industry did,” Mr. Jaffe said earlier this week. “I felt the industry didn’t make a case for (longer hours).”