Littler Mendelson. Photo: Diego M. Radzinschi/ALM

Donald Lewis, the former partner of Pierce Bainbridge Beck Price & Hecht who is ensnared in litigation with the firm, is now suing Littler Mendelson and Putney Twombly Hall & Hirson for defamation, accusing them of supporting a campaign to smear him after he was fired.

In an amended complaint Friday, Lewis added Littler and Putney Twombly as defendants to his defamation complaint against Pierce Bainbridge. The two firms have served as outside counsel to Pierce Bainbridge. Lewis' amended complaint, filed in Manhattan Supreme Court, seeks $45 million in total compensatory and punitive damages, along with other relief.

A spokeswoman for Littler said in an email, “We believe these allegations are without merit and plan to vigorously defend against them.” Michael Yim, a partner at Putney Twombly, declined to comment.

Pierce Bainbridge has said Lewis was fired after a staffer accused him of sexual assault and he violated the terms of his leave, but Lewis has said the firing was in retaliation for his criticism of partner John Pierce's financial shenanigans. Both sides sued one another.

In his amended suit on Friday, Lewis seeks to hold liable Littler, whose partner S. Jeanine Conley represented Pierce Bainbridge in presuit negotiations with Lewis and in its efforts to dismiss Lewis' suit, and Putney Twombly, whose partner Yim is described by Lewis as having spearheaded a sham investigation into the sex misconduct complaint against him. Lewis said he was suing the two firms and their two partners for their “direct and malicious participation” in Pierce Bainbridge's alleged campaign of defamation against him. He also added Pierce Bainbridge partner Caroline Beck to the latest version of the defamation complaint.

“Beck, Conley and Yim are well aware of Pierce's continued abuse of plaintiff, yet rather than take corrective ethical action, they have focused on aiding, abetting and facilitating the pathologically misguided Pierce Bainbridge war against plaintiff,” the new complaint states.

The amended complaint includes six claims: defamation, aiding and abetting defamation, violating the attorney-deceit law, New York Judiciary Law section 487, intentional infliction of emotional distress, aiding and abetting intentional infliction of emotional distress, and prima facie tort.

The amended complaint is the latest development in a bitter, multifront dispute. Lewis first sued Pierce Bainbridge and Putney Twombly in May after months of discussing a potential settlement, withdrew the suit on the same day in hopes of resolving the matter, only to be met by a suit in California state court by his former firm that accused him of extortion, among other things. Lewis refiled his complaint the next day, and the defendants have sought dismissal. Lewis filed his second suit, claiming defamation, in June against Pierce Bainbridge.

Pierce Bainbridge has said in statements and LinkedIn posts that Lewis was “credibly” accused of sexual assault by a staffer and was terminated for violating the terms of his suspension. Lewis has shot back with criticism of the internal investigation and claims that Pierce Bainbridge lied to Pravati Capital, a litigation funder that lent money to the firm.

Marc Mukasey, who represents Pierce Bainbridge, couldn't immediately be reached for comment.