CHICAGO — Gov. Pat Quinn on Tuesday rejected a bill to expand gambling in Illinois, including a new land-based casino in Chicago, saying the proposal lacked sufficient regulatory oversight.

With two of his predecessors in prison, the Chicago Democrat had made it clear he must preserve his political integrity in the plan, which also proposed establishing four new riverboat casinos and allowing slot machines at racetracks.

The most glaring omission from the bill "is the absence of strict ethical standards and comprehensive regulatory oversight. Illinois should never settle for a gaming bill that includes loopholes for gangsters," Quinn said in a statement.