CHICAGO (From news reports) -- R. R. Donnelley & Sons Co. said in a filing Friday that it delivered a letter to representatives of Chatham Asset Management LLC in response to discussions regarding Chatham's non-binding, conditional indication of interest to buy it.

Chatham offered to buy Donnelley for $7.50 a share in October, but Atlas Holdings has since offered to buy the company for $8.52 a share.

Chatham owns about 15% of R.R. Donnelley's shares, and is its largest bondholder.

Donnelley said it is prepared to engage with Chatham regarding its interest in potentially making a binding proposal.

The company said it proactively reached out to Chatham with a confidentiality agreement that would enable it to provide Chatham with confidential information and have discussions regarding its indication of interest.

Donnelley said in its letter that the confidentiality agreement terms it is offering to Chatham are consistent with the terms that Atlas has already agreed to in its confidentiality agreement and are consistent with the terms required of all other parties that come forward during the go-shop period or thereafter.

Donnelley said it is ready to engage with Chatham and consider a proposal that its board of directors can compare with the agreement reached with Atlas, which equates to a total enterprise value of $2.1 billion.

The company also said Chatham's proposal is missing key substantive terms of a potential transaction, including the transaction structure, equity and debt financing sources, as well as evidence of financial wherewithal to complete a transaction.