Hendon Reform Synagogue has postponed a vote on a merger with Edgware and District Reform Synagogue.
The shul's council had recommended union with the larger congregation as a "wonderful prospect" for the community, established in 1949. The vote was due to have taken place this Sunday.
But more time is being given to a group of Hendon members to explore the possibility of relocation further north-west, believed to be in the Mill Hill area.
The shul said the vote would now be held "after the summer".
Although Hendon still serves around 700 families, it has an ageing profile and little more than 10 per cent of members live in the area.