Southern Housing Group has amalgamated with two of its subsidiaries, James Butcher Housing Association and South Wight Housing Association.
The three social landlords, which manage 25,000 homes between them, will now operate as Southern Housing Group Limited.
The group is also setting up resident service panels in each of its regions: London, south, Thames Gateway, west and Isle of Wight.
Tom Daley, group chief executive, said: ‘Our simplified structure will enable us to make further economies of scale across our geographic spread. The money we will save will be used to improve our services for our residents and local neighbourhoods across all parts of the group.’