About a quarter of the nation's banks lost a combined $10 billion to $15 billion in the wake of the federal government's takeover of mortgage giants Fannie Mae and Freddie Mac, a new industry survey found.

In the survey, the American Bankers Association reported that 27% of the nation's 8500 banks held preferred shares in Fannie and Freddie in their investment portfolios. The shares are expected to be worthless.

The...