The purchase of the 27 titles will cost £18.75m.
North London & Herts Newspapers includes the Enfield Advertiser, Enfield Gazette, Haringey Advertiser, Edgware & Mill Hill Press, Potters Bar & Borehamwood Press, Hendon & Finchley Press and Barnet & Whetstone Press.
The Yellow Advertiser has ten editions, covering Basildon, Havering, Chelmsford & Maldon, Brentwood, Castlepoint, Southend, Thurrock, Ilford & Redbridge, Barking & Dagenham and Epping & Waltham Forrest.
The South London Press & Mercury Group publishes the twice-weekly South London Press, Lewisham Borough Mercury, Greenwich Borough Mercury, Bexley Borough Mercury, Streatham, Clapham & West Norwood Post and Mitcham, Morden & Wimbledon Post.
The sale is expected to be completed at the end of August.
The Wharf, is not included in the sale and is to be retained by Trinity Mirror as it covers Canary Wharf which is home to the group’s headquarters.
Tindle Newspapers currently owns more than 200 titles and 14 radio stations.
Its portfolio includes the Cambrian News, Abergavenny Chronicle, Pulman’s Weekly News, Tenby Observer and West Somerset Free Press, as well as the Wellington Weekly News, which it bought from Northcliffe last October.
In March this year Sir Ray Tindle, founder and owner of Tindle Newspapers, said he planned to make a bid for some of the titles put up for sale by Trinity Mirror, but also said he may sell off some Tindle’s own assets as he hoped to “ease off a little during 2007″.
Sir Ray, who served in the Devonshire Regiment in the Second World War, dreamed up his idea of a family newspaper group on a troopship in 1945 – and the first title was launched in the 1960s with the £300 demob money given to soldiers at the end of the war.
Sir Ray said today: “I am delighted with this purchase of newspapers dating back to 1833, 1859, 1865 and 1976.
“We have met some of the management and are most impressed. We look forward to welcoming them and the staff into the family.
“Our current figures show that small local newspapers are standing up very well in current conditions. These new ones will magnificently add to that category.”