The future of Manchester United, the world's richest soccer club, could be in the hands of two publicity-shy Irishmen who made their money from horse racing.

John Magnier and J.P. McManus hold nearly 29 per cent of the club, which has received a bid approach from an unnamed suitor, and have said they are long-term investors.

But the tycoons -- who own a string of thoroughbred winners -- are thought to be willing to sell at the right price. What that is, they won't say, but if they do decide to sell it could pressure other shareholders to follow suit.

The Irish duo have steadily built up a their United stake -- currently worth over 200 million pounds -- through their investment vehicle Cubic Expression.

It is thought their aim in building up the holding is mainly to give them greater sway over the way the business is managed than with an eye to a takeover. In January, the two forced Manchester United to announce an internal review of transfers after threatening to demand an internal audit.

A person familiar with the situation said the Irish duo are not interested in running a football club, and now see their holding only as an investment.

But their major shareholding also gives them significant clout to block a bid.

"It is hard to imagine that anyone could mount a serious bid without talking to the major shareholders," a source familiar with the matter told Reuters.

Manchester United said on Monday it had received an approach, but declined to give details. Industry sources said U.S. sports tycoon Malcolm Glazer was planning a bid of more than 650 million pounds.

ODDS-ON

The takeover interest comes exactly a week after the club warned of a 14 million pound hit to profits this year due to lower TV revenues and less money from European football after it finished third in the premier league in 2003-04.

Getting out with a profit estimated at between $85 million and $125 million could be a safe bet for the Irish pair but, as men who made their fortunes in the betting industry, they may be willing to hold out for higher returns.

Born into an Irish farming family in 1948, Magnier is arguably the most powerful figure in the world bloodstock business via his County Tipperary-based Coolmore Stud, which also has operations in Kentucky and Australia.

Almost as reticent, but equally passionate about horses and racing, is Magnier's long-time associate McManus, a legendary gambler known in Ireland as "the Sundance Kid" or "the man who broke the bookies".

A former bookmaker himself, McManus, who reportedly scooped 250,000 pounds from one bet in the early 1980s, is best known to racing fans through his horse Istabraq, which won three Champion Hurdles at Cheltenham.

The two men form the core of the so-called "Coolmore Mafia", an exclusive coterie that also includes Irish millionaire Dermot Desmond, the biggest shareholder in Scottish soccer club Celtic and owner of a small interest in Manchester United.