Most Rangers fans must wonder how on earth their team, playing in front of home crowds of 51,000 and competing in the first group stage of the Champions League elite with its revenues of £12 million, can possibly be in financial trouble.

The answer is that Rangers do have money worries, but they are small in comparison to those of the main owner, Sir David Murray’s company — Murray International Holdings (MIH).

And getting Rangers’ difficulties sorted out quickly does look like a key part of saving MIH, on which not just Sir David’s family fortunes depend, but also the jobs of 3,500 people.

Indeed, the demands of keeping MIH going will be the key reason why Sir David stepped down from the Rangers chairmanship, for the problems at the family business vastly overshadow those of the football club.

Up to 2008, when the present recession began, MIH’s business looked reasonably healthy. It spanned a range of activities — buying and selling 330,000 tonnes of steel a year, running office and shopping complexes valued at £649 million, running call centres for other companies who paid MIH £50 million, and managing investment funds of £48 million.

Altogether, these activities produced for Sir David’s business an income of £542 million, of which Rangers’ share was £52 million or slightly less than 10 per cent.

Profit for the whole year was £20.6 million, which Sir David said was “particularly pleasing” given that the credit crunch had begun to bite six months earlier.

The looming problem, however, was that this performance had been built on a massive pile of debt. By the beginning of 2008, MIH’s net debt was a staggering £759.3 million, massively up from £468.3 million two years previously.

In that context, Rangers, which is 60 per cent owned by MIH, and its debt, which has reportedly risen to £30 million, is rather paltry. And in normal times, MIH’s much bigger debt, which was 70 per cent of the value of everything owned by the company, could also be managed.

But these are not normal times. Sir David has three big problems at MIH. First the cost of borrowing money has gone up because the credit crunch has reduced the amount of money available to lend.

Unlike a mortgage on a house, which is typically a loan to be repaid over 25 years, big loans to companies are made available only for periods of between one and five years.

At the start of 2008, MIH had bank loans of £704.4 million, of which £432 million had been lent for just two years or less. Every time Sir David renews these loans, the cost he has to pay in interest charges will go up. But then there is a second problem. Just as with a mortgage, when a bank has the security of being able to repossess a home if the borrower fails to make the monthly payments, so with company loans a bank will have the security of being able to seize the business assets.

However, recession means that the value of these assets has plummeted. The value of Sir David’s property empire is likely to have fallen by nearly half since 2007. The value of his steel companies and their stocks will also have dropped because construction work has shrivelled. So the assets may by now be worth less than the total debt.

Recession means a third problem — the income to pay the cost of borrowing money has also shrunk. Banks are selling fewer mortgages, so MIH’s call centres are handling less work and falling stock-market values have shrunk the returns from investment funds.

Sir David could solve a lot of these problems by selling bits of the business. That’s where Rangers come in because, unlike most of the rest of the MIH business, football clubs have not lost as much of their value as have, say, office blocks.

The first priority of Lloyds Bank, which has let most of MIH’s borrowings, is to keep MIH going so that it can recover most, if not all, of its money.

So selling Rangers, at the very minimum to recover £30 million of debt, is probably a top priority.

But to get the best price, it wants to make sure that Rangers are in the best financial condition they can be. Recession has already slashed the income from TV companies, notably through the collapse of Setanta, and will also have cut income from selling replica shirts and all the other merchandise.

So cutting costs, and players’ wages are by far the biggest cost, is the top priority. Selling a player not only cuts the wage bill, but also has the handy bonus of bringing in transfer fees to cut the debt.

The bank can force this to happen because it will have the security of MIH’s and Sir David’s shareholdings in the club. The unspoken threat, if Rangers do not cut costs and fail to make any debt repayments, is that the bank will seize the shares and Sir David will get nothing from any subsequent sale.

Lloyds is not running Rangers, but Alastair Johnston, Sir David’s successor as chairman, has little option but to do what the bank wants.