Sandy Muirhead, co-founder of mid-market firm Phoenix Equity Partners, has stepped down as a managing partner, as the firm transitions its management away from its original founders.

According to a statement from Phoenix released Wednesday, Muirhead, who oversaw the spin-out of the firm from Credit Suisse First Boston more than 10 years ago, has stepped down from running the firm but will continue in his role as chairman of its investment committee before "reducing his time commitment to the firm in mid-2015".