CLEVELAND, Ohio -- David Franklin, who joined the Cleveland Museum of Art as its ninth director a little over three years ago, has resigned his post, effective immediately.

He said in a prepared statement that he’s is proud of the museum’s accomplishments during his tenure, but has “concluded that it’s time to spend more time on research and writing.”

Franklin has agreed to act as a consultant to the museum during a transition period in which museum Trustee and donor Fred Bidwell, co-founder of Cleveland's Transformer Station gallery, will act as interim director.

Museum Board Chairman R. Steven Kestner said he was surprised by Franklin's resignation.

“Nobody can imagine what they’d do in this situation," he said. "This is not something anybody plans for.''

He declined to elaborate on the reasons for Franklin’s departure.

“He resigned for personal reasons,” Kestner said. “I really can’t say more than that.”

Cleveland businessman Peter Raskind, also a museum board member, will head a committee that will choose an executive search firm and seek a new director. The museum has not set a timetable for the process.

Raskind has also served as former interim CEO of the Cleveland Cuyahoga County Port Authority and the Cleveland Metropolitan School District.

Franklin’s departure hits the museum months before the completion of an eight-year, $350 million expansion and renovation it calls the largest cultural project in Ohio history.

Kestner said he was not worried that Franklin’s departure would hurt the museum’s capital campaign, which has $97 million to go to pay for the $350 million project.

“I think we’ll be fine, I really do.” Kestner said. “We’ve tried to start some conversations with people, which we have, and the response has been very supportive and I expect it will continue to be.”

Grafton Nunes, president and CEO of the Cleveland Institute of Art, said of Franklin's departure, "it's a blow. I will say it's a blow.

I think David has brought extraordinary intelligence and humanity and commitment to the museum."

Nunes added, "I’ve really enjoyed his [Franklin's] sense of humor and his artistic values and he will be missed.

I will miss collaborating with him."

During his three years at the museum, Franklin oversaw the completion of several phases of the expansion and renovation and reinvigorated special exhibitions and publications. The museum earned national attention for its high-tech Gallery One, an educational center featuring a 40-foot-long interactive display of works from the museum's collection that dovetailed with a new mobile app for the Apple iPad.

Franklin spent the summer rescuing an exhibition on Sicilian antiquities, which the region's cultural authorities had threatened to cancel if the museum refused to pay fees imposed at the last minute. Franklin instead offered to send a show of masterpieces from the museum to Sicily in 2015.

Most recently, Franklin held a press conference with Michael Bennett, the museum's curator of Greek and Roman art, announcing the publication of an exhibition catalog focusing on the museum's controversial purchase in 2004 of an ancient bronze statue of Apollo.

The catalog, which defends the purchase, is likely also to stir controversy among archaeologists who say that collecting works such as the Apollo, which has gaps in its ownership history, encourages looting of ancient sites.

Franklin’s departure continues a period of turbulence in museum leadership. The institution has had four directors since 2000, including Katharine Lee Reid (2000-2005); Timothy Rub (2006-2009); and Deborah Gribbon (2009-2010).

Reid retired for personal reasons on the eve of the vote by trustees to launch the expansion and renovation. She moved to Chapel Hill, N.C. to spend time with family members including her father, former Cleveland museum director Sherman Lee, who died in 2008.

Rub left Cleveland after three years to become director of the Philadelphia Museum of Art. Gribbon, a former director of the J. Paul Getty Museum in Los Angeles, acted as an interim director for the museum, but is counted on the museum's website as one of its former directors.

The museum hired Franklin away from the National Gallery of Canada in Ottawa, where he had risen over 12 years from curator of prints and drawings to deputy director and chief curator.

At the time, trustees were eager to find a director who would stay long enough to see the institution through the completion of its expansion and renovation in December and beyond its centennial in 2016.

Kestner, who chaired the search committee that hired Franklin, said that he's confident the new opening will be an attractive one.

"I believe the museum has never been in a better position," he said, citing a string of balanced budgets, the nearly completed expansion and a recent record of popular exhibitions and programs. "This is a very different job than it was four years ago."