Long-life private equity funds, which operate for longer than the industry-standard 10-year span, are a "logical evolution" of the buyout industry, according to Stewart Kohl, co-chief executive at US firm The Riverside Company.

US-based private equity firm Carlyle Group announced in October that it had raised its first long-life fund, attracting $3.6 billion of capital for a vehicle that would hold onto assets for 15 years.