The company, which itself has a stock market value of only £200m, will also increase top-up payments to its own pension scheme, which has a deficit of nearly £400m, to £43.8m per year from £36.2m.
Mr Fox said: “I don’t think there is any concern about the price. I know that our shareholders will be entirely supportive of this transaction.”
He highlighted the inclusion of Mr Desmond’s celebrity magazines, including OK!, among the reasons why it will stump up more than the £125m Mr Desmond paid for the Express and Star in 2001.
Following the takeover, Mr Desmond will become one of the biggest shareholders in Trinity Mirror with a 9.4pc stake. Mr Fox said the billionaire would be a normal shareholder, although he will also be the Express and Star’s landlord for at least five years and has agreed to buy a total of £32m of advertising for his Health Lottery business.
Following a failed round of negotiations in 2015 Mr Desmond said he hoped the Mirror chief executive would “Fox off” and launched a price war against Trinity Mirror.
Mr Fox said: “He sees that scale matters. It does. These businesses are stronger as a part of a bigger group. He’s been a man of his word throughout this process.”