Notting Hill Genesis will have 54,000 homes across London and a further 64,000 across the southeast, half of which are general needs homes with social or affordable rents.
The new organisation will have 170,000 residents, making it the largest provider of shared ownership tenure in the country.
The two organisations have combined reserves of £3.1bn and loan facilities of £3.5bn, generating annual turnover of £700m and a net surplus of more than £120m.
They estimate that joining forces will enable them to deliver 2,700 new homes a year – 400 more than would be achievable separately.
Both Notting Hill Housing and Genesis Housing were founded in different forms during the 1960s. Notting Hill Housing was set up by Rev Bruce Kenrick, who also founded Shelter, the charity that supports the homeless. Genesis Housing was created as Paddington Churches Housing Association. Both have evolved and grown over the years but their core purpose remains to provide homes to the less well-off across London and beyond.
Genesis chair Dipesh Shah is chair designate of the new organisation. Paul Hodgkinson, from Notting Hill Housing, had recently extended his term of office to oversee the transition to merger, but never intended to remain past that point.
Kate Davies from Notting Hill Housing has been named chief executive designate, with Elizabeth Froude, currently Genesis deputy chief executive, being appointed deputy chief executive designate of Notting Hill Genesis.
“Uniting two associations with a common culture, a common vision and an aspiration to enrich their social purpose augurs well for the future of the merged entity,” said Dipesh Shah. “I look forward very much to being part of it and to helping the new organisation on its journey.”
Genesis chief executive Neil Hadden, who has agreed to step aside, added: “I have always believed that there should be more consolidation within the sector so that our capacity can be utilised better to provide more homes and improved services for our customers. To that end, this merger makes complete sense and I am pleased to have been involved in getting it off the ground. I look forward to continuing to lead Genesis until the merger is complete in early 2018.”