Former Paddy Power chief executive Andy McCue is to leave the newly-formed Paddy Power Betfair at the end of April.
He was named chief operating officer of the new company when it was formed.
Mr McCue spent almost ten years at Paddy Power - he says that now is the time for a change, he added that he believes that the joined firms will be "greater than the sum of its parts."
"I have thoroughly enjoyed leading and working closely with a great team of people who have created a dynamic and successful business. I feel now is the right time to pursue new opportunities and, in doing so, wish everyone in Paddy Power Betfair the very best for the future," Mr McCue said in a statement.
Elsewhere in the betting world - UK bookmaker William Hill has said that it believes that its profits will fall by up to £25m this year, as new measures to curb online gambling come into place.
It has also warned that results went against the bookmaker at this year’s Cheltenham festival and that this will also hit its bottom line.