MGM Resorts International said Monday it plans to build a $675 million casino on the waterfront in Bridgeport, Conn., seeking a possible fourth casino in the state and adding another battle to a continuing feud with Indian tribes about the future of gambling in the region.

MGM, along with real-estate firm the RCI Group, will seek legislative approval for the casino and 300-room hotel at Steelpointe Harbor, a long-planned waterfront...