Quite what went on between the two men must remain, for the most part, a secret. They had lunch, where the talk was of footballing and equine athletes. Ferguson, new to the racing game as an owner, has become nearly as passionate about the equine turf as he is about the footballing one. His best horse, Heritage Hall, is trained at Magnier's Ballydoyle Stables in Co Tipperary, and Magnier has acted as an unofficial adviser to Ferguson over his bloodstock purchases. All the evidence looks to the favour having been returned.
There is little doubt that Ferguson would rather do business with the Magnier consortium than either Edwards or Rupert Murdoch, whose ultimately abortive bid for United was being examined by the Department of Trade and Industry at the time of the intriguing lunch.
It has been said that Magnier - almost no one refers to him by his first name - is the most powerful man in Ireland. That may be stretching it, but he is certainly one of the richest and most powerful men in the high- stakes world of international thoroughbred racing and breeding.
A devout Catholic whose family has been in the horse-trading business since the 1850s, Magnier attended Ireland's premier Catholic school, Glenstal Abbey in Co Limerick, leaving at 15 on the death of his father to run the family farm.
His fortune was made - and continues to be partially generated - by spotting trends and controlling markets in the international bloodstock world. The Coolmore stud in Co Tipperary is the engine room of a business that operates on five continents and employs more than 600 people.
Coolmore is now Europe's premier stallion farm, and anyone who is serious about breeding a winning racehorse has to do business with Magnier. From the Aga Khan to the Queen through to the hugely wealthy ruling family of Dubai, the Maktoums, at one time or another all have sent mares to stallions owned by Coolmore in the hope of breeding that elusive commodity - a Classic-winning racehorse.
Magnier purchased Coolmore in 1974 in partnership with his father-in- law, the legendary trainer, Vincent O'Brien (with whose daughter, Susan, he has five children) and the pools magnate-turned-racehorse-owner, Robert Sangster.
Today the operation is owned entirely by O'Brien and Magnier, although precise financial details are difficult to come by. Coolmore operates as an unlimited partnership and as such has no need to publish accounts. And that is just the way Magnier likes it. Although a man with little public ego, he has private vanity as his well-publicised houses dotted around the world testify. He enjoys his success.
Home away from home is a golf- course villa near Marbella in Spain (naturally Sean Connery is a friend) and a mansion in Barbados, known as Gatwick because of its size and a constant stream of traffic going in and out. He keeps a permanent staff of 35 at the property, which has its own cinema, gym and chapel.
The jewel in the Coolmore crown is a horse called Sadler's Wells from which the Coolmore operation earns on average pounds 15m per year - some years a great deal more. There are 50 other stallions at Coolmore, but Sadler's Wells dominates the worldwide horse-racing industry like no other. He is the greatest sire of his generation and the cornerstone of Magnier's fortune.
But it really could have been any commodity for Magnier. "If potatoes were a cash crop with tax exemptions and potential for global domination he would own the potato exchange," says one who knows him well.
As it is, horses are his business but - like the Barclay twins - it could have been anything. He was always going to be a successful businessman.
Ireland holds particular attractions for Magnier, whose fortunes are so heavily vested in the ability of a stallion to fornicate and produce racehorses that will turn into champions and become prize stallions themselves.
In 1969, his friend the former Irish Premier, Charles Haughey, pushed legislation through the Dail that saw all earnings from stallions given tax-free status. But his friendship with Haughey came back to plague the intensely private Magnier when it was revealed earlier this year at a tribunal of inquiry that a cheque for pounds 10,000 issued by Magnier to a third party ended up being used to fund the establishment of a Haughey family business. To understand a little more about Magnier, it helps to look at the company he keeps. He socialises and does business with a tight coterie of self-made men.
Bahamas-based billionaire Joe Lewis is a close associate (although Lewis has denied any involvement in the United deal), having bred the Coolmore- based stallion Lake Coniston. But that is a deal Lewis would rather forget. He sold the horse for 22,000 guineas (pounds 23,100), but it went on to be-come a champion and now makes that during a day at stud.
Others close to Magnier include gambler JP McManus, stockbroker Dermot Des- mond and former bookmaker Michael Tabor, who owns horses in partnership with Magnier. With sunglasses glued to the top of his head, his face in an almost perpetual scowl, Magnier strides around the world's racecourses on first-name terms with everyone. But for someone so open about his presence, he remains secretive about what he actually does - and what, outside bloodstock, has added to his considerable fortune.
"He and his coterie live up to their `Coolmore Mafia' image. They love wearing sunglasses and talking out of the corners of their mouths. I certainly do not think you would want John Magnier as an enemy," says one follower. "And they are absolutely fearless when it comes to spending money," he says poignantly.
Magnier, McManus and Tabor are known as the "Three Musketeers" in in racing circles and they never fail to attend the Cheltenham Festival where they gamble prodigious amounts - not so much for the returns as the craic. That may well be the reason they are sizing up Manchester United - as one-upmanship to Joe Lewis, who owns a large slice of Glasgow Rangers.