Credit card issuers are cutting credit limits, or simply closing a growing number of accounts.

Just how much credit will the big credit card companies eliminate?

More than half is the astounding answer from Meredith Whitney, the Wall Street analyst who became famous for predicting the current banking crisis.

In an opinion piece she wrote for the Wall Street Journal, Whitney says consumers have used about $800 billion of the $5 trillion in credit card credit on their accounts.

But the amount of available credit was reduced by $500 billion in the final three months of 2008 and by the end of 2010 Whitney expects the amount of credit available to consumers on their cards will be down to about $2.3 trillion.

While cards have always slashed the credit limits for customers who fail to pay their bills, they're doing it for all sorts of other reasons now.

We've seen reports of credit limits being dramatically reduced -- from $40,000 to $4,500, in one case -- based on where the customer lives and what they do for a living.

In those instances, card companies targeted customers who live in states and work in industries, such as construction and banking that have been particularly hard hit by the mortgage crisis.

American Express has actually told cardholders that their credit lines are being cut based on where they shop and who holds the mortgage on their homes.

So it has come to this.

If your home loan is with a lender that's suffered from too many defaults, or you buy something at a store that's popular with people who haven't kept up with their bills, you're deemed to be less creditworthy purely by association, even if you have a strong credit score and history of making payments on time.

Once your credit limit is cut, it's hard to get it back up to a higher level.

To reduce future losses, companies are holding firm on the new limits. But because credit card companies each have a different method of judging applicants, shopping for a greater credit line may be your best bet.

Our extensive database of credit card rates and terms is a good place to start.

We also can help you find the best rewards cards and the best cards for balance transfers.