Private equity-backed initial public offerings are back in vogue after years on the sidelines and a long period when buyout firms sought exits from investments through sales to rivals.

Key European exits by buyout firms this year have almost all come from IPOs. They include: HellermannTyton, a UK cable-tie company from Doughty Hanson; Countrywide, the UK estate agent backed by Apollo Global Management and Oaktree Capital Management; and Partnership Assurance, a UK insurance company backed by Cinven.