The number of European bolt-on acquisitions - assets added to existing private equity investments – fell to a six-year low in 2009 despite expectations that firms would flock to the strategy.

The volume of bolt-ons in Europe fell by 41% to 203 last year, according to annual research by data provider mergermarket and UK buyout firm Silverfleet Capital. This represented the lowest figure since 2004 when firms carried out 169 bolt-ons.