Services including ICT, customer call centre, highways, revenues and benefits, payroll and HR are now being delivered in-house by Oldham Council.
Unity Partnership - which became a council-owned company in 2008 - had been delivering these services for the council for the past five years.
The council said the move would improve services for residents and allow closer working between departments.
Harry Catherall, chief executive of Oldham Council, said: 'Unity delivered some of the services that mattered most to Oldham residents, such as answering the calls of those in need through our call centre, managing our benefits service, and running our face to face customer support at Access Oldham.
'Bringing these services back to the council will allow us to build on improving customer satisfaction and the quality of the services we deliver, while at the same time delivering value for money for all of our residents.'
The move has seen more than 400 staff transfer over to the council.