Private equity heavyweights 3i have unveiled Simon Borrows as the firm’s new chief executive, taking over from the departing Michael Queen.

Queen joined 3i in 1987 and spent time as managing partner of the firm’s infrastructure business and global head of growth capital before taking up the reigns as chief executive in 2009.

Borrows moves over from his position as chief investment officer having joined the investor in October 2011. Prior to his role at 3i, Borrows was chairman of Greenhill & Co.

Queen stepped down from his role as chief executive in March after failing to deliver the ‘aggressive approach’ that shareholders wanted.

He initially came into his role tasked with reducing the company’s financial risk and oversaw a shrinking in the firm’s debt from £1.9 billion to £531 million between March 2009 and September 2011.

Borrows comments, ‘Whilst there are clear challenges ahead, particularly in light of the current uncertain macro-economic environment, I am committed to improving the performance of 3i and maximising long-term shareholder value.’

For the year to date 31 March 2012, 3i has reported a gross portfolio return of £329 million, down from £601 million the previous year, and has seen its portfolio value slip from £4 billion to £3.2 billion.

Over the period the firm invested £646 million and realised £771 million, compared to £719 million and £609 million for the proceeding 12 months.

Adrian Montague, chairman of 3i, adds, ‘[Borrows] has already made a significant positive impact as chief investment officer, bringing a fresh focus and discipline to 3i’s investment process.

‘This has been a challenging year for 3i and the stability of the Eurozone remains central to the outlook. Whatever the environment, we have a clear set of measures to maximise shareholder value and the returns to our co-investors in our funds.’