Private equity-backed businesses in Europe are flocking to North America for add-on deals, in search of higher returns amid stagnant economic growth back home.

The number of bolt-on acquisitions by private equity-backed European businesses in North America surged 76% last year, with 37 deals done, compared with 21 the previous year, according to European buyout firm Silverfleet Capital and data provider Mergermarket's European Buy & Build Monitor.