The biggest U.S. bank, Citigroup, lost $5.1 billion in the first three months of this year after making bad investments in securities backed by home loans. 

The losses reported Friday grew as more and more consumers also fell behind on car and credit-card loans.

Citigroup's managers say they will cut costs sharply, focus on the most fundamental parts of their business, and fire another 9,000 of their 370,000 workers.

It is the second major quarterly loss for Citigroup, and it is the latest in a wave of dismal bank earning reports over the past week.  Merrill Lynch revealed a $2 billion loss and 3,000 job cuts on Thursday.

Some information for this report was provided by AFP, AP and Reuters.