This Day newspaper's editorial director John Matisonn is to leave, the newspaper said on Thursday.
Matisonn joined This Day in September 2002 at the outset of the project to launch the paper "as a new quality national daily", and was a key player in the planning and execution of the newspaper, which was launched in October 2003.
Commenting on his decision to leave the company, Matisonn said he had accomplished what he came to This Day to do and "is very proud of the newspaper".
"It is a quality newspaper and will continue to grow as it becomes better known in the months and years ahead. I am delighted with its progress and I know that it is in fine hands as I move on to new challenges."
Nduka Obaigbena, chairman of This Day said he was sad Matisonn was leaving but he realised "that John's major work has been accomplished and that he was not attracted by the proposition of a routine situation within the company".
Graeme King, chief executive of This Day, said he would miss Matisonn's "enormous enthusiasm and energy for the newspaper".
"John is a source of great new ideas and his contribution to the founding of This Day will never be forgotten. I wish him well in the future." - Sapa