The Ohio Senate has passed a bill that would let electric car maker Tesla Motors operate three dealerships in the state. Its passage Tuesday comes after Ohio auto dealers struck a compromise to let California-based Tesla sell its electric cars at existing stores in Columbus and Cincinnati. The company also could open a third store, planned for the Cleveland area, but no others. No other automaker could operate manufacturer-owned stores in the state. Ohio was among states proposing to block Tesla from setting up additional direct-sales galleries on the grounds that they undercut traditional auto dealerships. Ohio auto dealers saw Tesla as a threat to a system in which nearly all dealerships are independently owned franchises that are separate from manufacturers. The House must still consider the proposal.