Twenty-two years after the General Assembly voted to outlaw slot machines, the Senate yesterday approved legislation that would allow their legal return in nine counties on Maryland's Eastern Shore.

A bill authorizing nonprofit groups to own and operate as many as five slot machines each, and requiring at least half the proceeds to go to charity, was approved 28 to 18 and sent to the House of Delegates.

Proponents said many nonprofit groups have continued operating slot machines undercover since the legislature voted in 1963 to require their phase-out over a five-year period.

Opponents have said they are certain Gov. Harry Hughes would veto the legislation. But Hughes yesterday appeared to leave the door open. He said he would have to take a "careful look" at the bill before taking a position.

If slot machines are to be legalized, Hughes said at his weekly news conference, they are going to have to be tightly controlled.

The Senate legislation would require fraternal, religious and veterans groups to own the machines they operate and offer gambling only at their principal meeting places.

The organizations would be required to annually report the income from the machines and how the proceeds are spent. Each machine would have to be equipped with a tamper-proof meter or counter that records gross receipts.