SJ Berwin has secured its second major instruction from Goldman Sachs' private equity arm, and its first from AXA Private Equity and Bregal Investments, on a deal that sees the houses investing in an existing private equity fund.

The top 15 City firm is advising the three buy-out houses on a £75m Penta Fund 1, owned by Penta Capital Partners.

Under the unusual deal, Goldman, AXA and Bregal are buying out one of the current investors and investing more into the fund, which was formed in 2000 with £125.5m.

The SJ Berwin team was led by corporate partners Mark Mifsud and Joanna Hamilton, assisted by corporate associates Nigel van Zyl, Kate Downey and Angela Newton.

The firm first acted for Goldman Sachs in September 2004 on its acquisition of two of Societe Generale's private equity funds, which led a combined value of €220m (£150m).

Goldman Sachs instructed SJ Berwin after working opposite the firm on a deal in February 2004. Then Mifsud acted for Vision Capital on its acquisition of a portfolio from CS Structured Credit Fund, in which Goldman Sachs Vintage Funds was one of the lead investors.

Mifsud said of the recent transaction: "It is consolidating our relationship with Goldman and other quality players and displaying our transactional and funds capabilities."

Penta Capital Partners was advised by Dickson Minto. Some investors also had US advice, with Goldman Sachs and AXA Private Equity additionally advised by Boston-based Ropes & Gray and New York's Weil Gotshal & Manges, respectively.