Charity specialist Wilsons has advised on the first outsourcing of a local authority adoption service.
The Salisbury-based firm acted for adoption agency Coram Family in a deal that handed Coram management of the London Borough of Harrow's adoption service.
The Wilsons team was led by partner Alison McKenna, head of Wilsons' eight-lawyer charity group. She said: "This is a perfect example of 'charitisation'. More than a third of charity income now comes from the state - we still have this idea of charities rattling their tins, but it's very outdated.
"The Government is committed to delivering this model of charities delivering public services, and this deal is just the tip of iceberg."
Harrow was advised by in-house lawyer Stephen Dorrian.
The transfer comes as local authorities across the UK struggle with a national shortage of qualified adoption workers.