On Thursday, Best Buy said its board appointed a global search committee to look for a new chief executive. It expects that search to take between six and nine months.

Dunn's departure comes on the heels of a $1.7 billion quarterly loss. He had laid out a plan last month to gradually transition the company away from big-box stores by shutting some, remodeling others, and opening smaller stores focused on mobile phones.

That plan, which the company says it intends to move forward with, called for the departure of 400 employees at the corporate and support levels.