The headline-grabbing €1bn-plus deals that typified the golden era of European private equity suffered a surprise fall last year as contracting credit markets took their toll in the second half, according to research published today.

Early last year mega buy-outs seemed to be propelling big private equity firms to new heights, culminating with the record £11bn ($21.6bn) takeover of the Alliance Boots pharmacy chain and triggering a fierce political backlash, notably in the UK.