NEW YORK (Reuters) - JPMorgan Chase & Co posted an increase in first-quarter profits on Friday as the biggest U.S. bank benefited from lower expenses. Net income rose to $6.53 billion, or $1.59 a share, from $4.92 billion, or $1.19 a share, a year earlier. The year-ago results had been reduced by 12 cents a share due to costs from its "London Whale" derivatives trades. Results for both periods included other special items. (Reporting by David Henry and Dan Wilchins in New York; Editing by Jeffrey Benkoe)