CHICAGO—  Private equity firm Chatham Asset Management is making a bid for  RR Donnelly. The dissident share holder , own approximately 14.9% of the outstanding common stock and  is the largest bondholder of Chicago-based RR Donnelley & Sons (RRD), is seeking to buy the remaining shares of North America's largest commercial printing company for $7.50 per share in cash. It would represent a 52.1% premium over RRD's closing price of $4.93 per share on Oct. 11. Chatham also noted it is willing to  subordinate its entire debt position, reducing RRD's total debt by 23%.  RR Donnelly is Canada's fifth largest printer according to Graphic Monthly's listing  of Canada's top  printers with sales around $250 million in Canada . RR Donnelly took over Moore Business Forms and all of their plants in Canada . They also own Annan & Bird in Mississauga.