For Yas Banifatemi, practicing international arbitration at a large law firm had stopped making sense.

She and her colleagues had for years operated “a firm within a firm” that had become Shearman & Sterling’s “crown jewel,” she said, but as the firm expanded its U.S. presence the global arbitration practice was feeling some unfortunate side effects. As Shearman grew its focus on the energy sector by adding dozens of partners in Texas, Banifatemi and the arbitration team found themselves increasingly conflicted out of matters for longstanding clients.