Williams is the second high-profile departure from Ewood Park since the Venky's takeover following the sacking of Sam Allardyce in December.
"With our new owners the Venky's Group, I have no doubt this is a new dawn for the club," Williams told the club's official website. "There is a new order, a new way of doing things and I believe the time is right for me now to move on."
Source: PA
Source: PA