Mr Desmond has made hundreds of millions of pounds from his ownership of the newspapers, and was similarly successful during a briefer period at the controls of Channel 5.
Sale talks between the two publishers were announced in September 2017, with rumours of an acquisition circulating for long before that.
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Furthermore, the group said it will deliver £20m in annualised cost synergies by 2020, with a significant amount of these savings achieved in 2019. It is good for our readers, good for our customers and good for our shareholders.
Job losses are feared after the publisher of the Daily Mirror struck a £126.7 million deal to buy Richard Desmond's newspaper and magazine stable. "We've had plenty of time to think about this carefully".
It publishes the Daily Record, the Sunday People and more than 200 regional newspapers, including the Birmingham Post and the Manchester Evening News.
The deal will be put to a shareholder vote on 27 February and if approved it is expected to complete on 28 February.More news: Tonight in PyeongChang: Curling gets underway with a new event
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Trinity will fund the cash element of the purchase price, the contributions to the Northern & Shell pension schemes, and transaction costs by the utilisation of a new £75m amortising term loan facility, which will be fully drawn, with the balance being drawn down from its existing debt facility and cash balances.
It also means that the right-leaning Express titles will be now owned by...
Once the dominant newspapers in the United Kingdom, both the Daily Mirror and Daily Express have seen their circulations decline steeply since the 1960s.
"This 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".
The newspaper industry faces many challenges, including the growing move to online readership and the dilemma between charging readers, who may then refuse to pay and get their news elsewhere for nothing, or giving away content and risk failing to cover costs through advertising.
The tycoon is now focused on a string of property ventures and a potential bid for the licence to run the National Lottery.