New York’s Citigroup Inc. said they would take billions of dollars in charges related to bad loans to high-risk U.S. homeowners.

Citigroup, the largest U.S. bank, said it would write off $5.9 billion for the third quarter because of expected losses on mortgage and consumer banking and because it had been unable to sell securities backed by mortgages and corporate-takeover loans. It said its third-quarter profit, to be announced this month, would slide 60% from last year’s $5.5 billion.