Mitchells & Butlers said more than half of the pubs in the acquisition of the majority of the Orchid Group will be converted to its existing formats and brands, which include All Bar One, Nicholson's and Crown Carveries.
Orchid was set up in 2006 and now features more than 200 pubs across seven concepts, including pizza kitchens and Thai pub restaurant Dragons.
Mitchells currently generates average weekly sales of £22,700 from its pub restaurants and believes the strength of its brands and experience will enable it to improve on the £15,300 per week made at the acquired pubs.
A further 77 pubs have recently received investment and will continue in their current format, while benefiting from purchasing synergies as part of Mitchells.
The Orchid estate, which was created following the purchase of 300 pubs from Punch Taverns, has many of its outlets in the South East and North West of England. Today's deal excludes a number of leasehold sites.
Mitchells is the UK's largest operator of managed restaurants and pubs, with an estate comprising more than 1,600 outlets.