Best Buy Co Chief Executive Brian Dunn suddenly resigned from the company during an investigation into allegations of personal misconduct, the electronics retailer confirmed on Tuesday.

"Certain issues were brought to the board's attention regarding Mr. Dunn's personal conduct, unrelated to the company's operations or financial controls, and an audit committee investigation was initiated. Prior to the completion of the investigation, Mr. Dunn chose to resign," said Claire Koeneman, an external spokeswoman for Best Buy. She would not comment on what the issues were.

Dunn could not be reached for comment.

In a statement issued by Best Buy earlier on Tuesday, Dunn said, "I have enjoyed every one of my 28 years with this company, and I leave it today in position for a strong future."

Best Buy said that G. Mike Mikan, a board member, would serve as interim CEO and that a search for anew CEO was underway.

The timing of Dunn's departure came as a surprise to Wall Street. Only two weeks ago, Dunn presided over the company's announcement of a plan to close 50 of its 1,100 large stores and cut 400 jobs.

But critics have complained that under Dunn's tenure, which lasted less than three years, Best Buy became a showroom for Amazon.com and other online retailers, with consumers going to Best Buy stores to check out electronics like high-definition televisions, then buying them elsewhere for less.

The company, seen as a bellwether in the consumer electronics industry, reported declines in same-store sales in six of the last seven quarters.