Countrywide Residential Lettings has acquired Specialist Lettings Management, which has offices in Bolton, Blackpool and Southport.
The deal takes the number of Countrywide branches to 204. SLM also has regional leasehold block management centres for Yorkshire and Merseyside.
"SLM is known in the North as a professional and successful lettings operation, which is overseen by a hugely experienced senior management team," said John Hards, managing director of CRL.
"SLM's network of offices are an excellent strategic fit with CRL and their branch locations sit well within our current network."
SLM founding managing director, Roger Henshaw, will remain in charge of its ongoing operations.