McAleese revealed his surprise decision to Barclays 120 staff last week. It is understood he will remain in the Irish arm of Britain's third-largest bank for a notice period of at least three months as a replacement is sought.

Claret Capital manages between 8bn and 10bn in assets and McAleese will be joining as chief operating officer in charge of the day-to-day running of the business. The Dublin-based investment firm is headed by media and aviation entrepreneur Domhnal Slattery, who recently opened a new office in the US.

"We are delighted that Tom is joining the firm and this is a strong endorsement for our business, " said Slattery. "His experience will help us grow Claret in the next phase of our development in the coming years."

McAleese joined Barclays Ireland from ABN Amro in 2003 after a stint at Guinness Peat Aviation, where new boss Slattery began his career before starting his own aviation financing firm, IAMG, in 1994.

Formerly a banker himself with Royal Bank of Scotland, Slattery has a wide range of business interests. He co-founded the Clare People newspaper and has a stake in cable TV station Channel 6.

Claret Capital recently funded JetBird . . . billed as Europe's first low-cost, on-demand private jet airline . . . to purchase 50 new Phenom executive jets with an option for 50 more.

The investment firm also injected 20m into a joint venture with former Labour party leader Dick Spring's Altobridge operation, which supplies mobile phone technology for ships and aircraft.

In a statement, Barclays Ireland chairman Donal Roche said he was searching for a replacement for McAleese and sources close to the bank expect a successor to be hired in-house "I am happy to confirm that the current strong management team in Barclays will continue to provide excellent service to our customers, grow our business and execute on the growth strategy in Ireland. Our search for Tom's successor is under way and a further announcement will follow in due course, " said Roche.

Banking sources said competition within the Irish bank to succeed McAleese has begun, with several names already in the ring. These include finance director James Kelly, head of business banking Adrian Doran, head of property finance Henry Cleary, and Treasury chief Ciaran Kane.