The National Association of Pension Funds (NAPF) and the Pensions Management Institute (PMI) have decided not to proceed with a merger.
The merger was intended to "create a stronger voice for pensions and retirement benefits in the workplace". However, after "extremely positive" discussions, the PMI decided that it was "best placed to pursue its strategic objective as an independent organisation".
Paul Couchman, president of the PMI, said: "We have explored many of the complementary areas of expertise that both organisations offer and have looked at the significant value a merged organisation could offer to members. The due diligence processes undertaken raised no issues or concerns on either side.
"However, after careful review by the PMI board and its council, we have decided that PMI is best placed to pursue its strategic objectives as an independent organisation. We remain committed to raising standards by providing our members with the highest quality pensions qualifications and look forward to announcing some exciting new initiatives in the near future."
Ruston Smith, chairman at the NAPF, said: "It is with disappointment that we make today's announcement. We must, however, respect the PMI's decision not to pursue this opportunity. The NAPF continues to fulfill the needs of our members by providing them with the high quality services they require, including education and policy solutions."
The decision was made following the announcement of the potential merger in October last year.