Aston Villa chief executive Paul Faulkner, a long-term business colleague of club owner Randy Lerner, has stepped down from the role.
Robin Russell, who had been chief financial officer at Villa Park, will become acting chief executive.
Faulkner said: "Villa is best in class in so many ways off the field. I only hope success on the pitch follows."
Villa chairman Lerner put the club up for sale in May but is yet to find a buyer.
Having previously been the club's chief operating officer, Faulkner was promoted to chief executive in May 2010, three months before then-Villa boss Martin O'Neill resigned.
The Midlands club have had three other managers in the four years following O'Neill's departure; Gerard Houllier, Alex McLeish and Paul Lambert.
On Monday Lerner released a statement stating he was focused on preparing for the new season and would not be distracted by looking for a buyer.
Villa, who finished 15th in the Premier League last season, announced last week that Roy Keane would be Lambert's assistant manager, replacing Ian Culverhouse, who was dismissed in May following an internal investigation.