Maryland voters approved the addition of slot machines to that state Tuesday, but any impact on Pennsylvania's growing slots industry could be minimal.

The Maryland referendum was one of several pro-gambling measures approved in elections around the country, but some proposals were defeated. Ohio voters soundly rejected a measure that would have created that state's first casino, in the southwestern corner of the state where it was unlikely to compete much with Pennsylvania slots parlors.

Maryland voters agreed to allow five slots operations in their state that could have a total of 15,000 machines. It could be two or more years before any open, as exact locations will have to be determined by a new commission. The only certain location now is Rocky Gap State Park, which is near Cumberland, Md. It will be the closest Maryland facility to Western Pennsylvania and the smallest in that state, with no more than 1,500 machines.

Joe Weinert, an analyst for Spectrum Gaming Group, expects the impact on Pennsylvania's slots patronage and revenue to be minimal from new gambling operations in the Baltimore and Annapolis areas and elsewhere in Maryland.

"But this is a real blow to Delaware," he said. Casinos there "will be challenged to retain their substantial basis of Maryland customers."

The tax breakdown in Maryland will not enable construction of grand resort casinos like those of Atlantic City, Mr. Weinert said. Operators will retain about one-third of the revenue gamblers provide -- less than the 45 percent they keep in Pennsylvania -- with the rest supporting state educational initiatives, the racetrack industry, local governments and other causes.

In general, the gambling industry across the country has been hard-hit by the recent economic slump. Pennsylvania is an exception, as October revenue figures from the Gaming Control Board continued to show the state's slots parlors avoiding the kind of drop-off from last year experienced in many other states.