More than four out of five public companies that been taken over by private equity groups failed to outperform, making public-to-privates the worst performing private equity deal, a survey has claimed.

According to accountancy firm Ernst & Young, only 17.6% of private equity groups that exited their take-private investments in 2006 and 2007 outperformed the public markets in terms of enterprise value growth, the headline value of a company including debt. This compared with 75% of acquisitions from a non-private equity-backed public owner.