Mr O'Reilly is understood to have approached Roy Greenslade, the former Daily Mirror editor, about having his old job back. The Heinz boss also has plans for a boardroom reshuffle and has drawn up a list of cost-cutting measures.
According to advisers in London and Dublin, Mr O'Reilly has decided that if he makes a move at all for MGN it will be on a strictly solo basis. They say he reached the decision after seeing how easy it was for Conrad Black to acquire effective control of Fairfax, the Australian group, with a minority stake.
'Fairfax is regarded as a template,' one Dublin adviser said. 'We have realised we don't need to own 100 per cent to exercise management control.'
By limiting himself to 29.9 per cent - the maximum purchase allowed before a full bid becomes compulsory - Mr O'Reilly will avoid having to go into the market and be able to go it alone.
At present John Talbot, the administrator from Arthur Andersen, the accountants, controls 56 per cent of the equity. Mr O'Reilly's Irish group, Independent Newspapers, can afford to buy a 29.9 per cent stake from him for around pounds 100m. Mr Talbot and National Westminster Bank, which has security over 33 per cent of MGN, would be more agreeable to a partial sale, the O'Reilly camp believes, if they thought their remaining shares would receive a lift.
Since they were relaunched two months ago, MGN shares have languished at around 60p, well below their May 1991 flotation price of 125p.
The prospective appointment of Mr Greenslade, who was widely regarded as a successful editor and is well liked by Mirror staff, may strike a serious blow to the attempt of Richard Stott, the current editor, to lead a management buyout. Mr Stott has faced an uphill task in persuading the City to back his bid.
Mr Greenslade, who was dismissed by Maxwell in March 1991 and has since worked as a consultant at News International, could not be reached for comment. But it is believed he has set his heart on a return to the Mirror - so much so that he has taken himself out of the running for other editorships - and has indicated he is willing to serve under Mr O'Reilly.
The Heinz boss's determination to seize control of MGN on his own will end speculation that he might join forces with other bidders. Despite obvious competition problems, other UK newspaper groups had been linked with Mr O'Reilly.
Lord Rothermere, the Associated Newspapers proprietor, who is a friend of Mr O'Reilly, has made no secret of his desire to see the Mirror, which was owned by his grandfather, Lord Northcliffe, returned to his family. United Newspapers has also been mentioned as a possible buyer.
Independent Newspapers already distributes the Daily Star in Ireland and Lord Stevens, United's chairman, was a guest of Mr O'Reilly at the races recently. Such speculation can now be discounted.
Mr O'Reilly, who has appointed Charterhouse in London to act on his behalf, is likely to emphasise that he needs no assistance.