Rich Ricci, the former chief executive of Barclays’ corporate and investment bank and once right-hand man of Bob Diamond, has emerged as the third-largest shareholder in fledgling European trading venue Aquis Exchange.

Ricci, an acquaintance of Aquis' founder and chief executive Alasdair Haynes, has taken a stake of just over 10% in Aquis, according to company filings published this week. The shareholder list is accurate as of December 31, 2013, according to a spokeswoman for Aquis who declined to comment further.