A £700m contract to provide community health and care in Bath and North East Somerset over the next seven years has been approved for Virgin Care.
The council said it was "an exciting new chapter in the integration of health and care services".
Trade union Unison said members were "anxious" about Virgin Care taking over and it would hold the firm "to the high standard the workforce deserve".
Virgin Care said it was "pleased to be chosen to deliver more joined-up care".
The deal will see Virgin Care take over more than 200 health and care services in people's homes and communities, in such areas as district nursing, dementia care and supporting vulnerable children.
'Paid a pittance'
Councillor Vic Pritchard, from Bath and North East Somerset Council, said: "Local people can look forward to a more joined-up and personalised service in the future, with the focus firmly on prevention and supporting people to maintain their independence."
John Drake, from Unison, said: "Many community health staff are paid a pittance, despite the long hours they put in and their dedicated work.
"Employees need clear recognition from Virgin that a well-run health service means investment in staff."
A Virgin Care spokesman said: "We're looking forward to working with the many outstanding professionals, and a range of great partners, to provide and oversee high quality, easy-to-navigate services which are shaped by the people who use them."
Services are to be transferred to Virgin Care on 1 April 2017.