The Storey family, which has owned a controlling stake in the group for 126 years, has pledged its shares to Johnston and will exit the business if the deal is approved by the Department of Trade and Industry next month.
Sir Richard Storey, who sat on the board from 1962 to his retirement as an executive last year, will make pounds 47.9m from his 18 per cent stake - nearly 90 per cent more than it was worth before bidding began. His sister Jacquetta Cator, with 16 per cent, will collect pounds 42.6m. Other family members will get up to pounds 3m between them.
Sir Richard, whose great-grandfather Samuel founded P&S with the Sunderland Echo in 1873, agreed the Johnston offer after a drawn-out auction involving at least four bidders.
Johnston approached P&S chief Charles Brims in November, but talks were ended in days. In January, Johnston went hostile, building a 14.99 per cent stake and unsuccessfully tendering for another 10 per cent.
Mr Brims then opened the bidding to others, prompting interest from Newsquest, NewsCom and others.
Two weeks ago Mr Brims re-opened talks with Johnston, which was willing to raise the offer from pounds 16 a share. P&S helped by selling its One Stop chain of stores for pounds 68m.
The current bid, at pounds 22.25 a share, is a premium of 14 per cent to P&S's close on Monday, and an 88 per cent premium on before the January announcement. Shares in P&S jumped 14 per cent to 2,222.5p.
Angela Maxwell, media analyst at Sutherlands, said the deal was a full price for P&S, and would give Johnston sufficient size to survive in a shrinking industry.
Tim Bowdler, chief executive of Johnston, said the price was justified by synergies. P&S's head office was likely to disappear. Savings could also be made by cutting administration and printing costs. Shares in Johnston eased 0.5p to 272p.