Merrill Lynch Q4 loss $9.83 billion vs $2.35 profit Merrill Lynch:end-Q4 subprime mortgage exposure $2.7 billion Merrill Lynch: end-Q4 foreign mortgage exposure $9.6 billion Merrill Lynch: end-Q4 Alt-A mortgage exposure $2.7 billion Merrill Lynch: Q4 subprime write-downs $1.6 billion Merrill Lynch: Q4 commercial mortgage write-downs $126 mln