Former Buzzfeed president Jon Steinberg is to leave Mail Online after 18 months as North America chief executive.
Steinberg, whose move to the Mail was announced in June 2014, is to leave at the end of this year.
According to Mail Online publisher and chief executive Martin Clarke, Steinberg has "played a leading role in building our digital media assets in the US".
This included DMGT's acquiring of Elite Daily, a US website which calls itself the "voice of generation Y", and the launch of content marketing company Truffle Pig. Clarke said: "He also led investments on behalf of DMGT in Taboola, Brit+co and Tigerbeat."
He added: "Our commercial progress has been tremendous, reflected in our year on year revenue growth of over 45% and the doubling of our direct advertising sales revenue.
"Our priority now is to concentrate on these investments and execute on our organic growth strategy. We have very amicably agreed that this does not play to Jon’s passions and strengths in pursuing significant acquisitions and partnerships, and he has therefore decided to move on and find his next challenge. He has agreed to stay until the end of the year and will work closely with me to ensure an orderly transition.
"We wish him continued success in whatever he chooses to do next and thank him for his contribution to the growing success of our businesses in the US."
Steinberg said: "It has been a fantastic period of growth for DailyMail.com in the U.S. I thank Martin and my team for a great experience, building and innovating an advertising business that we are all very proud of."