CHICAGO—  The board of RR Donnelley (RRD) has unanimously determined that Chatham Asset Management’s revised proposal to acquire the business constitutes a ‘Superior Proposal’.The bidding war over the future ownership of RR Donnelly intensified earlier this week when it received an unsolicited proposal from Chatham – RRD’s largest investor– to acquire all of the RRD shares that it does not already own for $10.25 per share in cash. Its prior offer for the business was $9.10 per share, while a deal for RRD to be taken over by affiliates of Atlas Holdings had already been agreed in early November at $8.52 per share.  Will there be additional offers ? If Chatham break RR Donnelly up or will they replace Senior Management . Chatham's discontent with Senior Management is what started the bidding war .