(L-to-R) Faith Gay and Philippe Selendy of Selendy & Gay.

Ten former Quinn Emanuel Urquhart & Sullivan lawyers now at Selendy & Gay have challenged part of their former firm's partnership agreement, arguing in Manhattan state court that it includes an unethical requirement for departing partners to give a cut of their legal fees back to Quinn Emanuel for any clients they took to the new firm.

The Selendy & Gay lawyers, who include founding partners Philippe Selendy and Faith Gay, along with eight others, filed a petition—dated May 11 but entered into the public court docket on Tuesday—looking to shut down an arbitration proceeding initiated by their former firm in California. The court filing marks the latest in what has been a less-than-amicable split by the Selendy & Gay team, a group of litigators who left Quinn Emanuel early this year and officially launched a new firm in February. Previously, Quinn Emanuel founder John Quinn made negative comments about the departure, specifically focusing his ire on Gay.

At issue in the Manhattan state court petition is a “forfeiture-for-competition” provision in the Quinn Emanuel partnership agreement, which purports to give the firm a claim over an 18-month period to 10 percent of any legal fees earned from clients that former partners took with them to a new firm.

The Selendy & Gay lawyers maintain that while they agreed, as former Quinn Emanuel partners, to confidentially arbitrate disputes in Los Angeles under California law, the forfeiture-for-competition provision puts them at odds with New York's rules of professional conduct for lawyers. The petition argues that this is the first time, to the Selendy & Gay team's knowledge, that Quinn Emanuel has ever sought to enforce the provision against partners who left the firm.

“New York's ethical rules strictly forbid any agreement that restricts the right of a lawyer to practice after termination of the relationship created by that agreement,” the Selendy & Gay lawyers wrote in the petition. “Although the petitioners do not dispute that they signed the QE partnership agreement, each of the petitioners, as a lawyer licensed in New York, is bound to abide by the New York ethical rules and is subject to discipline in this jurisdiction.”

Representatives for Quinn Emanuel did not immediately respond to a request for comment.

In addition to Selendy and Gay, the petition was joined by firm partners David Elsberg, Andrew Dunlap, Maria Ginzburg, Sean Baldwin, Christine Chung, Jordan Goldstein, Yelena Konanova and Jennifer Selendy. (Jennifer Selendy is Philippe Selendy's wife.)

The petition goes on to argue that firm founder Quinn and Quinn Emanuel's New York office managing partner Rick Werder, who notified the Selendy & Gay lawyers about the arbitration, are also both licensed in New York. As a result, the petition said, they are bound to “not order or direct other New York-admitted lawyers to engage in, or refuse to correct, conduct that violates” the New York legal ethics rules.

The Selendy & Gay lawyers further allege that after they left Quinn Emanuel, Quinn sought assurances that they would not “poach” top associates from their former firm, in exchange for an agreement that Quinn Emanuel would not seek to enforce the forfeiture-for-competition provision. Selendy & Gay refused to sign onto any anti-poaching agreement, believing that, too, would run afoul of New York ethics rules. The petition alleges that Quinn Emanuel's arbitration demand followed soon after those anti-poaching discussions ended.

The Selendy & Gay lawyers have also filed a motion to stay the arbitration proceeding. In a brief filed Tuesday supporting that motion, they argued that a permanent stay is warranted in this case. They stated that after Quinn Emanuel filed its arbitration demand, the Selendy & Gay lawyers proposed that they ask a New York ethics panel to rule on whether the forfeiture provision is enforceable. However, Quinn Emanuel rejected that proposal, according to court documents.

The court filings constitute another development in a contentious split between the Selendy & Gay lawyers and their former firm. In January, Quinn Emanuel made the unusual move of pre-empting the news of the imminent departures with its own statement saying that the firm did not expect the departure of a group of lawyers would have much impact on its business. Quinn later accused Gay—in a reply-all email to a farewell message from Gay to her former Quinn Emanuel colleagues—of “ingratitude” and charged that she and others secretly conspired to organize their spin-off.

“I was less disappointed, actually, in the fact that she and others were leaving than in the stealthy way it was done, which was at odds with the close relationship we thought we had and which she professed to still have,” Quinn told ALM in February, after his “ingratitude” email was first posted online by the blog Above the Law.

A spokesman for Selendy & Gay declined further comment.