After scrambling for months to keep his grip on the bank he helped build from a scrappy Southern outsider to the nation's largest in assets, Bank of America chief executive Kenneth D. Lewis said he will resign by year end.

The 62-year-old Lewis, who has led the Charlotte, NC, bank since 2001, notified the board of his decision on Wednesday. A person close to him says Lewis was fed up with the criticism that haunted him following the takeover of Merrill Lynch.