Lloyds Banking Group is negotiating a £400m acquisition of CPA Global, the patent and legal services group, underlining how the private equity arm of the partly state-owned bank now dominates the UK’s shrinking buy-out market.

Most private equity groups have been sidelined since the financial and economic crisis began. But LDC has completed 10 buy-outs this year, a sixth of all deals and three times more than any rival, according to Dealogic.