Countrywide Financial, the biggest mortgage lender in the United States, is scrambling to stay alive amid a tightening credit crunch.

The company announced this morning that it was drawing down an entire credit line of $11.5 billion.

Its shares tumbled 14 percent in early trading. 

The announcement comes a day after a Merrill Lynch analyst reduced his rating on Countrywide's stock to "sell" and outlined how the company could be forced to seek bankruptcy protection. Countrywide's shares fell 13 percent on Wednesday.

"Countrywide has taken decisive steps which we believe will address the challenges arising in this environment and enable the company to meet its funding needs and continue growing its franchise."
Related LInks:

• Reuters: Countrywide debt protection costs double
• David Wilson: Countrywide's Fate, Cerberus's Hell