More U.S. customers changed banks last year: survey Mon Feb 27, 2012 7:06am EST (Reuters) - Nearly 10 percent of customers of U.S. banks moved their accounts last year, often after they became frustrated with fees and the quality of service, market research firm J.D. Power and Associates said on Monday. The rate of customer defection from a primary bank to another institution was 9.6 percent, up from 8.7 percent the previous year and 7.7 percent two years before, the firm said, citing data gathered in November and December. One-third of customers of the biggest banks and large regional institutions who switched said fees were the main reason they looked for a new bank. More than half of customers who cited fees as the reason to defect said their bank had provided poor service. "New or increased fees are the proverbial straws that break the camel's back," said Michael Beird, director of the banking services practice at J.D. Power, a unit of the McGraw-Hill Companies Inc. Reporting by David Henry in New York; Editing by Lisa Von Ahn