Private equity firm New Mountain Capital has turned to Simpson Thacher & Bartlett for counsel on a $1.3 billion deal to recapitalize and take control of AmWINS Group, the largest wholesale insurance broker in the United States.

The deal’s terms call for New Mountain to take over rival buyout firm Parthenon Capital Partners’ majority AmWINS stake, which the latter acquired in 2005. AmWINS employees, who own part of the Charlotte-based company with Parthenon, will continue to hold more than 30 percent of the insurance broker after the recapitalization, according to the agreement.

AmWINS filed for an initial public offering seeking to raise up to $115 million in 2007, but withdrew its plans to sell shares later that year. (The company’s name is an abbreviation for American Wholesale Insurance Group.)

Charlotte-based Robinson Bradshaw & Hinson, which advised AmWINS on its IPO plans, is representing the company on the New Mountain deal through corporate partners David Dabbs and W. Scott Dove.

Dabbs, who once served as general counsel for AmWINS, has handled a number of matters for the company over the years. Donna Hargrove is AmWINS’s current general counsel, having been appointed to the position four years ago.

Simpson Thacher M&A partner Peter Gordon in New York is leading a team from the firm advising New Mountain on the recapitalization. Gordon and Simpson previously represented New York–based New Mountain as one of several majority shareholders in reinsurance company Paris Re on its $2 billion sale to PartnerRe in 2009.

Paula Bosco, a former in-house lawyer at Citigroup and UBS PaineWebber, is chief compliance officer for New Mountain, which has about $9 billion in assets under management.

One of New Mountain’s portfolio companies is Stroz Friedberg, a New York–based investigations and digital risk management firm founded by former FBI agent Edward Stroz and ex-federal prosecutor Eric Friedberg. Last month, Stroz Friedberg formed an e-discovery alliance with legal process outsourcer Pangea3, named the best provider in its field last year by sibling publication the New York Law Journal.