Bob Diamond, the former chief executive of Barclays, has taken a 20% stake in the French broker Kepler Cheuvreux as part of his ongoing efforts to capitalise on a changing regulatory landscape for European investment banks.

The deal is Atlas Merchant Capital's most notable investment in Europe since its purchase of a controlling stake in the UK stockbroker Panmure Gordon in March 2017. Investing alongside Atlas is Edmond de Rothschild Equity Strategies, which has taken an 8% holding.