Berwin Leighton Paisner (BLP) has won former client Isis Equity Partners back from Olswang after advising the private equity house on its exit from clothing company Fat Face to Advent International for approximately £100m.

It is understood that BLP won the mandate to act for Isis, which held a minority stake in Fat Face, after pitching against DLA Piper Rudnick Gray Cary, Olswang and Pinsent Masons.

Partner Anthony Grossman, who led the team at BLP, said this is the first time the firm has acted for Isis in six years. “I used to act for Isis back in 1996 when it was called Baronsmead and then passed the relationship over to Chris Mackie while he was still at BLP. But when Chris left BLP to join Olswang, he took Isis with him,” he explained.

A source at Olswang said that the firm “still does a lot of work for Isis” and that BLP won the instruction because it was already advising Fat Face’s management. According to reports, Fat Face’s management initially considered floating the business, but later ditched that idea in favour of a sale.

Grossman’s relationship with Fat Face dates back to a meeting with the company’s chief executive officer Louise Barnes in her previous role at Monsoon and he advised the clothing retailer when it floated seven years ago. Barnes subsequently joined Fat Face and in her new role is understood to have recommended Grossman to Isis.

Advent was advised by Lovells associate Jonathan Wood, with assistance from private equity rainmaker Marco Compagnoni.

Wood said: “The founders of Fat Face, Timothy Slade and Julian Lever, retained a significant interest in the company.”

DLA Piper and Pinsents declined to comment.