Cobbetts has won a unique role as the preferred legal supplier to four northern councils.
Bury, Rochdale, Oldham and Stockport Councils have entered into a joint legal services partnership – believed to be the first of its kind in the UK public sector.
Cobbetts will advise the four councils across all practice areas, while the councils will pool their knowledge and expertise and minimise running costs by instructing just one firm.
Headed by Cliff Mills, the Cobbetts public sector team already works with a number of public authorities including NHS trusts. The firm also advises bodies such as Lancashire County Council in other areas of law.
A spokesman for the councils said the new arrangement would provide better value for taxpayers.