Lawmakers gave initial approval Tuesday night to legislation that would add Maine to the growing list of states that have legalized betting on athletic events.

The Senate voted 19-15 and the House voted unanimously to approve a bill that would allow individuals 21 or older to gamble on professional and most collegiate sports in Maine. Bets could be placed either at physical locations – such as existing casinos or off-track betting parlors – or online via the mobile apps that account for the majority of sports gambling nationwide.

The bill faces additional procedural votes in both the House and Senate. But if the measure is enacted into law, Maine would join roughly a dozen states that have legalized sports betting since the U.S. Supreme Court struck down a federal prohibition last year.

The bill, L.D. 553, would create two different tax rates for sports betting in Maine. Licensed “bricks and mortar” facilities, such as casinos, would be taxed 10 percent, while mobile-only platform operators would pay 16 percent tax on their revenues.

The bill has faced little opposition, although Maine’s casinos and online platform operators have been lobbying for different versions of the legislation.

Members of a legislative committee had debated whether to require mobile betting operators to be connected or “tethered” to another licensee with a physical facility in Maine. Supporters of “tethered” licenses argued it would help support existing gambling-related businesses that hire Maine workers and pay local property taxes.