UK bookmaker Paddy Power Betfair early Monday announced the unexpected exit of its Chief Executive Officer Breon Corcoran after unconfirmed reports this weekend that the Dublin-based online and retail sportsbetting gaming operator was in the market for a successor.

The news comes on the heels of the £5 billion merger of betting exchange Betfair and Paddy Power completed in February 2016. The 46-year-old Corcoran is seen as the driving force behind the largely successful merger.

Ahead of trading Monday on the Irish Stock Exchange (ISE) the bookmaker announced that after 16 years with Paddy Power and its predecessor companies, Corcoran would be replaced by Peter Jackson, former WorldPay CEO, according to The Irish Times. Jackson, who has only been with the payments provider since March, will reportedly join the UK bookmaker later this year.

The unexpected news reportedly saw Paddy Power Betfair shares hit a 21-month low trading down more than 5 percent in early trade to £74.50.

The 41-year-old Jackson joined Betfair in 2013 as a non-executive director and sat on the Paddy Power Betfair board. The move by Jackson comes after the agreed £7.9bn takeover of Worldplay in July by JP Morgan and US card company and rival Vantiv. Jackson has reportedly worked for HBOS, Lloyds Bank and Santander and between 2010 and 2015 served as the head of foreign exchange company Travelex.

Paddy Power Betfair Chairman Gary McGann, commented: “The board’s unanimous selection of Peter follows a thorough global search for an individual with the skills and expertise to match the ambition of the Group. The combination of his executive expertise together with his understanding of the Paddy Power Betfair business as a non-executive director uniquely positions Peter to assume the role of CEO and lead the group in its next stage of development.”

McGann added, “Breon has been talking with me and the board about his long-term plans and accordingly, some months ago, we intensified our focus on executive succession planning to ensure an orderly transition.” And, “While we will be sorry to see Breon leave, we are delighted to have appointed a candidate of Peter’s calibre to succeed him,” according to the news agency.