Who knew that selling so many copies of "Flipping for Dummies" would be their own undoing?

The credit crisis engulfing America’s banking system yesterday threatened the independence of Borders, the retailer of books and DVDs, which put itself up for sale and admitted that it had been forced to seek emergency funding.

Borders, which yesterday reported annual sales of $3.8 billion (£1.9 billion) for 2007, said that it had appointed JPMorgan Chase and Merrill Lynch, the Wall Street investment banks, to “explore strategic alternatives”, including a sale of the entire company or a break-up.