Private equity houses have long been twitchy about pension liabilities at their portfolio companies. But the issue came in to the spotlight in dramatic fashion back in September 2008, when it emerged Duke Street had been forced by the Pensions Regulator to contribute about £8 million to top up the pension scheme of retailer Focus DIY after the private equity firm had sold it.

It was the first time the regulator had hit a private equity owner with a chunky retrospective bill. At the time, it was feared the implications for UK private equity would be great, with firms called on to top up pension deficits in ailing portfolio companies. Not surprisingly, it has been rare to see companies with pensions problems acquired by buyout firms ever since.