Former Chief Exec David Temme will focus on the new stadium and delivering it as soon as possible. All other duties have been handed to Ridsdale.
He will take responsibility for general running of the club including hiring and firing, matchday events, ticketing, security and redundancies.
The Echo claims the news will be made official in the coming week.
It's also said that Ridsdale, who came here as an advisor to Sam, could in future become a director of the club.