Casino operator stocks with major exposure to Macau fell sharply Tuesday, including Las Vegas Sands, Wynn Resorts and MGM Resorts, as China eyes tougher regulations.

The proposed rules call for the removal of current sub-concession system, the appointment of government delegates to oversee gaming operators and the creation of an illegal deposit crime, according to a macaubusiness.com report.

In 2002, Macau granted only three gaming concessions. One each to: SJM Resorts, a subsidiary of SJM Holdings; Wynn Resorts (Macao), a subsidiary of Wynn Resorts; and Galaxy Casino, connected to Galaxy Entertainment Group.