Best Buy CEO Hubert Joly shocked leaders at the Minneapolis Institute of Arts by resigning as the museum’s board chairman on the eve of its centennial year.

Joly said he recently began a relationship with an unmarried woman on the museum’s staff and stepped down “to address any potential or perceived conflict of ­interest.” Joly, who is divorced, felt their friendship posed a conflict with his responsibilities and chose to give up the post rather than the relationship.

“I have recently begun seeing a new person in my life,” Joly said in an e-mail to the Star Tribune. “This person happens to work at the MIA. As a result, I have offered to not finish my term … This is now a purely private matter.”

Joly’s departure comes at an important moment for the Twin Cities’ leading art museum, which hopes to use the centennial to boost its reputation on the national stage.

“I’m absolutely shocked,” said Reid MacDonald, a member of the board’s executive committee. “He is a charming and quite charismatic person who seemed to love his work there. He did an elegant job with the board, helped with fundraising and created a great spirit about the [museum].”

MIA Director Kaywin Feldman, who is in Europe on museum business, could not be reached for comment. As chair of the American Alliance of Museums, she is noted for her advocacy of professional standards of conduct.

What’s next

At the board’s request, Joly will continue in his post through the museum’s annual meeting on July 17, finishing the first year of what would have been a two-year term. Typically the outgoing leader is succeeded by the vice chair — currently philanthropist Mary Ingebrand-Pohlad — but Joly’s midterm departure alters that dynamic. A new board, elected that day, will pick someone to fill the remainder of his term. It is unclear whether Joly would remain on the board.

His departure is not expected to derail planning for the centennial, which includes an exhibition of gilded treasure from Austria’s Habsburg empire opening in February and a traveling show of 100 master drawings from the museum’s collection that opens next week.

“All those plans are in place, funded and ready to go, so we won’t skip a beat,” executive committee member John Himle said.

Regularly ranked among the country’s top 10 art museums, the MIA has a staff of 250 and a collection of 87,000 objects that span centuries of world culture in all fields, including ancient Chinese bronzes, European paintings, American Indian artifacts and contemporary photography. Last year, it attracted a record setting 680,000 visitors.

Past officials weigh in

Diane Lilly, a past board chair and current member, said Joly had sought her counsel last month.

“He’s an honorable guy and wanted to do the right thing,” she said. “I didn’t advise him at all; he made his own decision, which I thought was great.”

MacDonald, who missed the executive committee meeting at which Joly announced his departure, said the resignation was “a very dignified step.”

“When you’re in a position of power and authority, you’re at risk when you mess with staff,” MacDonald said. “It clearly would be the wrong thing to be both board chair and having a relationship.”

Himle, whom Joly succeeded as board chair, declined to comment on Joly’s relationship but said “I take him at his word that he felt he needed to step away, and I respect his position. The board is overall very grateful for [Joly’s] leadership and the energy he brought to the job.”

Asked if Joly would remain on the board, Himle said, “I don’t think so.” But he added that Joly “made it clear that he’s going to support the institution and remain involved, though not as aggressively as he has been.”

Joly’s personal life made news last year when he sold $10.4 million of Best Buy stock to cover the cost of his divorce. The company had to reassure investors and industry analysts that the sale did not signal the CEO’s loss of confidence in his company but was simply a personal matter.