First Chicago boosted its loan-loss reserve.

The Chicago-based bank holding company it is adding $800 million to its bad-loan account, becoming the latest of several major U.S. banks to take such action to cover shaky loans to developing countries. As a result, First Chicago said it expects to report a $700-million loss in the second quarter and a loss of between $420 million and $450 million for the full year. First Chicago, parent of First National Bank of Chicago, is the nation’s 11th-largest bank holding company.