By Al Yoon and Matthew Goldstein

NEW YORK, Oct 20 (Reuters) – Houston attorney Kathy Patrick represents a group of powerful mortgage investors trying to wring money out of Bank of America, but many legal experts say her chances of winning are slim.

For the second time in two months, the Gibbs & Bruns partner has sent a letter to a big bank trying to get some measure of financial relief for her clients who hold $16.5 billion of home loans packaged into bonds.