Chris O’Kane has stepped from his role as group chief executive officer of Aspen Insurance Holdings Ltd after the completion of the company’s takeover by US private-equity group Apollo Funds.

Mr O’Kane has led the insurer and reinsurer since it was set up in 2002 in response to market opportunities in the wake of the September 11 terrorist attacks on New York and Washington.

Apollo announced the completion of the deal this morning and Aspen’s shares ceased trading on the New York Stock Exchange and the Bermuda Stock Exchange.

Glyn Jones has stepped down as Aspen chairman and will be succeeded by Mark Cloutier, who will assume the roles of executive chairman and group CEO.

Mr Cloutier stepped down from his previous role as executive chairman of London-based insurer Brit Ltd in December last year. He was CEO at Brit from 2011 and became executive chairman in January 2017.

Mr O’Kane also ceases to be a director. Also leaving the Aspen board with immediate effect are Albert Beer, Matthew Botein, Gary Gregg, Heidi Hutter, Karl Mayr, Bret Pearlman and Ron Pressman.

John Cavoores and Gordon Ireland will remain as directors and will be joined on the Aspen board with immediate effect by Josh Black, Alex Humphreys, Gernot Lohr, Gary Parr and Michael Saffer, as well as Mr Cloutier.

Mr O’Kane said: “Seventeen years ago, with 38 colleagues, $600 million of assets and a vision, we formed Aspen. As a result of hard work, determination and an unwavering dedication to our clients, Aspen is now a force in the reinsurance and insurance markets with over $12 billion of assets and around 1,150 employees.

“I am extremely proud of our accomplishments and I cherish the relationships and friendships, both within Aspen and in the broader market, which we formed along the way.

“I would like to thank all my colleagues at Aspen as well as our clients and brokers for all their considerable support over the years and it delights me to see Aspen poised to go from strength to strength under the new leadership of Mark Cloutier. I wish Mark and Aspen every success for the future.”

Aspen said its 5.95 per cent and 5.625 per cent preference shares will remain issued and outstanding and listed on the New York Stock Exchange.

Alex Humphreys, partner at Apollo, said: “We are excited for our funds to be acquiring Aspen as it embarks on the next chapter of its development. We are delighted to be working with Mark again following our successful investment together in Brit Insurance.

“Mark has a long and successful track-record in the insurance sector and we believe he is ideally placed to lead Aspen through a period of transition to substantially improved profitability.

“We look forward to working with him and Aspen’s talented management team to drive value creation over the coming years.”

Mr Cloutier said he felt honoured to be appointed as the CEO of Aspen.

“I truly believe that the company benefits from strong underwriting talent and specialised expertise, which makes it ideally positioned to deliver innovative solutions to the increasingly complex risks faced by its customers.

“I am very excited about what Aspen can achieve in the coming years. I would like to thank Chris for his key role and support over the last few months and for making the transition from public to private so seamless.

“He has built an impressive franchise over the past 17 years and we wish him well in his future endeavours.”

Apollo was advised by Willis Towers Watson and Libero Ventures and Sidley Austin LLP served as its legal counsel on this transaction. Goldman Sachs and JP Morgan Securities acted as financial advisers to Aspen and Willkie Farr & Gallagher served as its legal counsel on this transaction.