Governor Deval Patrick will sign a new tribal casino compact today with the Mashpee Wampanoag approved by the Legislature last week.
The federal Bureau of Indian Affairs also must approve it.
Under the compact, the tribe would give the state 17 percent of its gambling revenues if its proposed Taunton resort casino is the only one in the southeast region, and 21 percent if it's the only one in the state. The state's share would drop to 15 percent if a slot parlor opens in the region. The state would get nothing if another commercial resort casino opens there.
The 2011 state law that authorized up to three resort casinos gave temporary exclusivity to a federally recognized Indian tribe in the southeast, but the area has been opened to other applicants.