Last September, Kim Taylor was feeling a bit nervous. The Kirkland & Ellis M&A partner was walking into the first face-to-face negotiation between her client, private equity firm Apax Partners LLP, and Endo Pharmaceuticals Inc. over the sale of Apax’s Qualitest Pharmaceuticals. Taylor was not a rookie: She had represented clients in more than $3 billion of M&A and private equity deals in the prior two years alone. But this deal was particularly important. Apax was a major client, and Taylor had represented the private equity shop on its original acquisition of Qualitest three years before, making her feel even more invested in a successful outcome.

Then there was her opposition: Eileen Nugent, a prominent M&A partner at Skadden, Arps, Slate, Meagher & Flom and cohead of the firm’s private equity group, was representing Endo. Nugent’s stellar reputation and 13-year history with the drugmaker was a bit intimidating, and Taylor wanted to "show well," she says. There was also Nugent’s gender. The prospect of negotiating against another woman as lead counsel, a relatively uncommon event, added an element of self-consciousness to an already high-stakes situation. "There’s a little bit of additional pressure, especially because with women, there can be a more narrow margin of what is effective negotiating and what people characterize as nasty," Taylor says.