The Meadows Racetrack & Casino joined Pennsylvania's other slots parlors yesterday by winning permission to double its space where smoking is allowed, taking up half of the casino.

The Pennsylvania Gaming Control Board accepted a plan from The Meadows to allow smoking throughout the gaming floor of one of the two synthetic-fabric, tent-like structures in its temporary casino. The smoking area is the section of the casino patrons enter first.

Smoking will be prohibited in the casino's second room, which is in the rear of the facility in a separate structure connected by passageways.

The changeover was to be completed by today, Meadows spokesman David LaTorre said.

Because of the amount of smoking typically seen in casinos and the state's reliance on revenue from them, the slots operators won an exemption in Pennsylvania's Clean Indoor Air Act, which took effect in September. Initially, they were allowed to keep 25 percent of their slots area open to smokers.

The law enabled casinos to apply after 90 days to expand their smoking areas to as much as 50 percent if their smoking-permitted slot machines were generating more revenue on a daily basis than the smoking-prohibited slots.

Pennsylvania Revenue Department figures by December showed a significant difference in revenue between the smoking and nonsmoking areas in all seven of the casinos, and all of them applied for expansion to 50 percent. The machines in the one-quarter of The Meadows where smoking was allowed generated more than twice as much revenue, about $544 daily compared with $269 for slots in nonsmoking sections.

The Meadows has 1,825 slot machines, and somewhat more than half of them will actually be available to smokers because the smoking-allowed room has more machines than the casino's rear section. The law permits smoking on 50 percent of the gaming floor, which, depending on the layout, can actually include more than half of the machines.

No decision has been made on how smokers and nonsmokers will be separated in the permanent casino of The Meadows to open in the spring, Mr. LaTorre said. It will have one large room with space for nearly 4,000 slot machines. Most of the casinos have designated one large section of the floor for smoking and banned it on the other half, a gaming board spokesman said.