Mr MacKenzie, who was partly backed by his old boss Rupert Murdoch, was the sole bidder for the company, after a bid by the station's current management team was withdrawn in July. His new company, TalkCo, is buying the 63 per cent of the station owned by its current parent, the European media giant CLT-UFA.
The deal values the station at pounds 24.7m. The existing management, led by programming director Paul Robinson and backed by the Guardian Media Group and United News & Media, is believed to have valued the station at pounds 20m.
Mr MacKenzie said he would be bringing new broadcasters to the station. One of his talents as a print journalist was as a talent spotter. The current editors of The Sun and The Mirror are both MacKenzie proteges.
However he once famously boasted of his ignorance of broadcasting and after a number of years at Mirror Group's Live TV, was happy to return to newspapers earlier this year before departing to launch his Talk bid.
He maintained yesterday that the all-talk format of the station was the key to its strength. "Commercial speech radio is particularly well-positioned to benefit from this growth, as has already been proved in the US and Australian markets. We will be looking to both new and established broadcast talent to capitalise on this opportunity."
The deal is now subject to approval by the Radio Authority. The involvement of Mr Murdoch in the takeover has provoked calls from some MPs for the deal to be halted.
In the past Mr MacKenzie has made no secret of his desire to run his own media business and is known also to be interested in moving into film and television production.
As well as Rupert Murdoch's News International, Mr MacKenzie's consortium is backed by Radio Investments and LMC Radio, a subsidiary of the US cable TV group TCI.
Mr MacKenzie was also advised by Apax Partners, the venture capital company which backed Chris Evans' successful pounds 84m take-over of Virgin Radio last year. The successful bid is also supported by MVI, a British investment company which already owns 35 per cent of the station.
Mr MacKenzie, formerly the deputy chief executive of the Mirror Group and before that editor of The Sun for 13 years, said yesterday: "Radio is a growth medium which is attracting an ever increasing number of listeners and share of advertising market."
Commercial radio's share of advertising revenue has been increasing by around a fifth a year during the Nineties and national franchises like Talk are thought by the City to represent unexplored potential. The big national stations will also be in the position to exploit the digital radio spectrum which might develop over the next 10 years into a distribution network for the internet.Reuse content