The repairs and maintenance, voids and major works contract begins at the end of September 2017 and will run for 10 years, with a break after the first four years.
Optivo was formed in May 2017 to bring together AmicusHorizon and Viridian Housing into one organisation.
Osborne Property Services’ team will be based in a newly-sourced office on the outskirts of Hastings. It will be shared with the Optivo contact centre team.
Optivo chief executive Paul Hackett said: “We’ve entered into this long-term partnership with Osborne in order to build on our sector-leading repairs service in Sussex. This will result in on-going benefits for Optivo and, most importantly, our customers.”