The publisher of the Daily Mirror newspaper has struck a £126.7 million deal to buy a string of titles from Northern & Shell, including the Daily Express, the Daily Star and OK! magazine.
Trinity Mirror will stump up an initial payment of £47.7 million, followed by £59 million between 2020 and 2023 and a further £20 million by issuing 25.8 million shares to Northern & Shell priced at 10p each.
The move marks a major shake-up of Britain's media landscape, bringing together the politically left-leaning Sunday Mirror, with more right-wing publications such as the Sunday Express.
The deal will also see Trinity Mirror seize control of Daily Star Sunday, celebrity magazines New! and Star, and a 50% slice of the Irish Daily Star.
Northern & Shell is owned by Richard Desmond, who acquired the Express titles in 2000 for £125 million.
Trinity Mirror chief executive Simon Fox said: "This deal is a really exciting moment in Trinity Mirror's history, combining some of the most iconic titles in the UK media industry.
"It is good for our readers, good for our customers and good for our shareholders.
"Northern & Shell's titles have a large and loyal readership, a growing digital presence and a stable revenue mix and offer an excellent fit with Trinity Mirror."
Trinity Mirror will also shift £41.2 million to the Northern & Shell pension scheme and make further payments of £29.2 million as part of the scheme's recovery plan.
The print media industry is grappling with a decline in advertising and any combination could herald cost savings and a shared cut of a larger advertising pool.
Mr Desmond, chairman of Northern & Shell, said: "The Express newspapers and our celebrity magazine titles have been a key part of the Northern & Shell portfolio for many years, and I am immensely proud of building them into one of the largest newspaper and magazine groups in the UK.
"Today's transformational transaction is a logical and natural next step in the evolution and consolidation of the media sector and will create a larger and stronger platform serving all stakeholders.
"In Trinity Mirror we have a great partner, who will be an excellent steward of the business going forward, and I am delighted to be able to retain an ongoing interest in the combined group."