In a sign of deepening turmoil, Hershey Trust board member Joan E. Steel resigned her position at the troubled $12.3 billion charity for impoverished children as the giant charity faces its latest investigation by the Pennsylvania Office of Attorney General.

The office has set a July 31 deadline for the trust to comply with its demands for reforms, which include the removal of three long-standing board members and other governance changes.

Steel, who lives in the Chicago area, was not one of the three board members the attorney general has been seeking to remove.

Her resignation also comes as the Hershey Co. candy giant - which is controlled by the Hershey Trust - has rejected a $23 billion offer from Mondelez International Inc. Some say Mondelez may make a higher bid. Both stocks traded slightly lower Monday.

Trust spokesman Kent Jarrell confirmed Steel's departure on Monday and said no reason was given when Steel gave notice over the weekend.

Steel could not immediately be reached for comment. She was compensated $106,500 for the most recent fiscal year, according to the charity's latest tax return.

With Steel's resignation, the trust board now consists of nine members.

Jarrell said that the boards - one to administer the $12.3 billion in charitable funds and the other to oversee the 2,000-student Milton Hershey School - can continue to function as they look for Steel's replacement.

In addition to Steel, three board members have resigned since late 2015, one of them Drexel University president John Fry.

Jeffrey Johnson, spokesman for the Attorney General's Office, said on Monday in response to Steel's departure that "this is an ongoing investigation, meaning we cannot comment at this time."