CHI Memorial Chief Executive James Hobson tendered his resignation.

His resignation will become effective July 12.

Hobson is pursuing a "new opportunity in health care leadership," said Dr. Christopher St. Charles, chief of staff for CHI Memorial in a released statement.

A national search firm has started the process of finding a new chief executive for the non-profit Catholic health care organization that has 700 affiliated physicians.

During the transitional period, Ricky Napper, senior vice president and chief operating officer, has agreed to take on leadership responsibility at CHI Memorial.

During Hobson's six year tenure, the hospital made a $300 million investment in the Chattanooga and Hixson campuses. The first phases of the Ooltewah campus were also developed. 

"As we look to the future, it will be critical to find a chief executive who can inspire the entire team, chart our future path and work with our physician partners to advance our Catholic healing ministry," said Charles Arant, chair of the Board of Directors for CHI Memorial.