The businesses sold include the South London Press, North London and Herts Newspapers and the Yellow Advertiser, at a value of 0.84 times 2006 revenues.
Sir Ray Tindle's Tindle Newspapers owns around 35 local titles including the North Cornwall Advertiser and the Abergavenny Chronicle.
The deal is the latest in a series of regional newspaper disposals secured by Trinity Mirror chief executive Sly Bailey.
Last month, the company sold 14 regional newspapers in Berkshire, including the Reading Chronicle, for £10m and 25 titles in Surrey, Sussex, Kent and Dorset to Northcliffe Media, part of Daily Mail & General Trust, for £64m.
Trinity Mirror is also close to divesting the Racing Post and its sports division, which it hopes to complete by the end of September.