In another complication in the bitter breakup of Cellino & Barnes, an attorney at the firm who is dating partner Stephen Barnes sued his longtime partner Ross Cellino on Tuesday for allegedly failing to pay her $936,000 she was owed for her work on a major case.

Ellen Sturm, a former Skadden, Arps, Slate, Meagher & Flom lawyer who moved to Cellino & Barnes in 2009, said in her complaint that she worked for years on a major case involving a 14-year-old boy who was badly injured by an exploding product. She said it was settled in 2018 on confidential terms that amount to "one of the largest personal injury settlements in U.S. history" and she was owed 8% of the firm's fee under a deal reached back in 2012.

After the case was settled, however, Cellino took the position Sturm had merely "handled the motions and appeals" that was a normal part of her salaried work, the suit claims. She said Cellino's protest was unprecedented and clearly driven by his animus for Barnes and said the firm's records would make clear that she "was involved in every facet of the case, including strategy, research and writing, document review, client contact, retention of experts" and more.

Cellino's actions "can only be an act of petty and vindictive retaliation," claims Sturm's suit, filed in Manhattan Supreme Court.

According to the suit, Sturm and two other Cellino & Barnes lawyers who worked on the case normally get 10% of the fee for matters they win or settle. Sturm said that Barnes, as president of the firm, negotiated with Sturm and the other two lawyers on the case, Dylan Brennan and Richard Barnes, who is Stephen Barnes' brother, to split 20% of the fee among them at the end of the case. The agreement was oral, she said.

Sturm's complaint said her relationship with Barnes has long been known and accepted by Cellino. But she said Cellino referred to her dismissively as "your girlfriend" in his combative emails with Barnes over the fee split.

In a statement, Cellino's lawyer, Terry Connors, who runs his own firm, suggested his client was simply taking a stand against nepotism.

"This lawsuit highlights why Ross dissolved Cellino & Barnes," Connors wrote. "He simply does not agree with preferential treatment for any lawyer in the firm and that will be one of the cornerstones of Cellino Law," Connors added, referring to his client's future law firm.

The case Sturm referred to wasn't explicitly identified, but based on details in her complaint and other accounts, it appears to be M.H. v. Bed Bath & Beyond, a case brought against several defendants over injuries sustained by the plaintiff when he was trying to light a gel candle.

Cellino & Barnes' fee from the M.H. case may have been $11.7 million, based on Sturm's claim to an 8% share worth $936,000. A footnote in Sturm's suit said: "The wages Sturm is owed are based on the attorneys' fee received by C&B minus expenses and disbursements, including a significant referral fee to another attorney, not the full confidential settlement amount."

Now Sturm is seeking more than $3.7 million, arguing Cellino & Barnes is liable for liquidated damages equal to triple her actual damages under state labor law.

Cellino said in an affidavit in early January that he and Barnes were on the cusp of finalizing their split, estimating it could be wrapped up in 30 days. A stipulated order of dissolution set court appearances for late January and Feb. 25 to hash out remaining issues, but Christopher Berloth of Duke Holzman Photiadis & Gresens, who represents Barnes, said Wednesday that negotiations were still underway and he couldn't give an estimate for when they conclude.

Cliff Robert of Robert & Robert, who represents Sturm, said in an emailed statement that his client is "a highly accomplished lawyer who will no longer tolerate being disrespected by Ross Cellino, Jr. She looks forward to holding him accountable in court."