Under the new arrangement, AMRA, Trinity Mirror Regionals' sales house representing more than 160 titles, will become a joint operating partnership between the two regional publishers from April 2012.
The move will bring an end to Northcliffe's relationship with third party sales house Mediaforce, which it has held since the start of January 2009.
When the relationship ends after the first quarter of 2011, National Classified advertising will be sold through Associated News & Media’s London Classified team, controlled by Martin Smith.
This team currently support Metro, London Evening Standard and Northcliffe Recruitment.
Steve Auckland, group managing director of Northcliffe Media, admitted that while Northcliffe's relationship with Mediaforce had been "excellent", it could not fulfil the geographical platform promised by a combined Trinity Mirror Regionals/Northcliffe package.
The joint partnership approach with Trinity's regional division, led by Georgina Harvey, was said to be "too compelling" to turn down.
Auckland said: "While our teams will miss the Mediaforce team, we are really excited at the prospect of gaining advertising revenue through this new arrangement."
The new sales partnership represents a significant move for regional newspapers, paving the way for economies of scale as well as the opportunity to offer a more comprehensive regional sell to the market.
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This article was first published on mediaweek.co.uk