The Jewish Association for Mentally Illness (Jami) is to merge with British Jewry's largest welfare organisation Jewish Care to create a single mental health service for the community in September.
The two organisations believe the tie-up will produce a better service across a wider area and cut overheads, but there is no intention to make redundancies.
Laurie Rackind, JAMI chief executive, said: "The merged service will allow JAMI to further its reputation as an outstanding mental health organisation, which will be of huge benefit to our community.
"We look forward to working with our colleagues at Jewish Care to make this happen."
Jewish Care head Simon Morris said: "Everyone involved agreed that the two organisations coming together to form one mental health service, and its potential to achieve much more than each organisation's individual efforts, was extremely beneficial for our community."