The councils of the two organisations have backed a plan to integrate their services.
BMRA members will vote on the proposals early next year, which, if approved, will take effect from April. It has yet to be decided what the merged entity will be called.
The trade bodies have been in talks over integrating their operations for two years, but have only agreed on a specific plan in the past six months.
The BMRA represents research agencies, while the MRS has traditionally represented individual researchers.
There have been frequent calls from within the industry for a single organisation to champion research and raise its profile with big-brand clients.