Tycoon Rupert Mudoch managed to acquire the Times group of newspapers in 1981 without a hearing before the mergers commission over his growing control of the British media.
Margaret Thatcher had a secret meeting with Rupert Murdoch just weeks before his 1981 purchase of the Times newspapers, newly released files show.
They show the contentious issue of putting Murdoch's bid for the Times and Sunday Times before the Monopolies and Mergers Commission was not raised.
The papers are being released by the Margaret Thatcher Archive Trust.
The official history of The Times book had stated there was no direct contact between the pair at that stage.
But a note in the files from Thatcher's long-serving press secretary Sir Bernard Ingham refers to a lunch with Murdoch at Chequers on 4 January 1981, "to be treated Commercial - In Confidence".
It details the News Group chairman's intention to buy the Times newspapers and its supplements from the Thomson family.
According to Sir Bernard, Murdoch told Thatcher he wished to make the Times operation profitable by introducing new technology and "a 25% reduction in overall manning".
During the meeting, he also stressed "the inevitability of progressing gradually".
"Nor did he accept that printing outside London was an option; he was firmly of the opinion that the titles must be printed in London", wrote Sir Bernard.
The files show the key political question of whether Murdoch's bid should be referred to the Monopolies and Mergers Commission (MMC) was not considered at the meeting.
At the time, Murdoch already owned the Sun and News of the World newspapers. The Fair Trading Act 1973 required that all significant newspaper takeovers be submitted to the MMC, unless the Secretary of State certified a paper was unprofitable and under threat of closure.
In the end, this clause enabled the purchase to go ahead without a referral because of major losses at The Times.
Redundancies had already been announced by the Thomsons, which owned the newspaper.
However, the Sunday Times had remained profitable during that period and was expected to return to financial health.
Following his successful takeover of the Times newspapers, Murdoch established the News International printing plant in Wapping, east London. It was here in 1986 that violent protests broke out over working conditions and the dismissal of employees.
The revelation of the 1981 meeting comes after recent evidence given to the Leveson Inquiry revealed an allegedly cosy relationship between the press and politicians in the UK.
The Leveson Inquiry was set up in July 2011 to examine relations between the press, politicians and police following the phone-hacking scandal at News International.