ANNAPOLIS — The Maryland Senate passed a bill Saturday that would let state voters decide in November whether a sixth Maryland casino should be built in Prince George’s County.

An amendment tacked on to legislation introduced earlier this year by Sen. Katherine Klausmeier, D-Baltimore, would also let voters decide whether to allow table games like blackjack and roulette. The vote authorizing the November referendum passed the Senate 37-9.

Lawmakers would have to meet again next year to work through the details of implementing the sixth casino, to be located in Prince George’s County, if it passes on the November ballot.

Any Prince George’s casino would be forbidden from operating before July 1, 2015, a good-faith effort to allow Maryland’s other five casinos a head start before facing competition, said Senate President Thomas V. Mike Miller Jr., D-Calvert and Prince George’s.

The referendum would not require a majority of Prince George’s County voters to approve the casino site as requested by the County Council — there weren’t enough votes to pass the measure in the House, lawmakers said.

The bill also adds another 1,000 slots to the statewide pool of gaming machines, bringing the state total to 16,000 slots.

A late-hour plan pitched by House leadership Friday significantly altered the Senate’s original gambling bill by allowing a sixth casino with table games, but no slots.

But casino investors and Senate leaders immediately panned the House proposal, leading to the speedy passage of another gambling bill.

“It’s insanity. Table games do not make enough to support the sort of casino we envision,” said W. Minor Carter, lobbyist for the Peterson Cos., developers interested in attracting a casino to National Harbor.

House Speaker Michael Busch, D-Anne Arundel, and other lawmakers were concerned the Senate bill favored the casino operators more than the state — a license holders’ share of slots revenue could have jumped from 33 percent to 48 percent in the Senate plan.

House leaders said Saturday they still don’t think there’s enough support in the House for any gambling bill with a vote on a Prince George’s casino.

“Most members… they just don’t have the appetite for a sixth casino,” said Del. Talmadge Branch, D-Baltimore city, the House Majority Whip.