The Express, one of seven national newspaper groups that backed the launch of the NMA, is said to have made the decision for financial reasons. Richard Desmond, the Express owner, is understood to believe that the group is not getting a sufficient return on its six-figure investment.
An NMA board source said: "It's been a problem getting money out of them (the Express) for some time now."
The source suggested that the Express' decision would not lead to other members pulling out, and was an isolated example of a newspaper attempting to make savings. The Express will no longer have direct access to NMA research projects, but may continue to gain some benefit from generic NMA marketing activity.
The NMA officially launched in July 2003 under the leadership of its chief executive, Maureen Duffy. It was backed by the major national newspaper groups, with the exception of the Financial Times, which said its agenda differed from other groups.
Each newspaper group funds the NMA in return for research and marketing initiatives designed to raise the profile of national papers. The NMA also runs an awards scheme for creative agencies.
Stan Myerson, the joint managing director and ad director at the Express, was unavailable for comment.