Banks are responding to the troubled economy by jacking up fees on their checking accounts to record amounts.

Last week, Citigroup Inc.'s Citibank started charging some customers a new $10 "overdraft protection transfer fee" to transfer money from a savings account or line of credit to cover a checking-account shortfall. Citibank had already raised foreign-exchange transaction fees on its debit cards and added minimum opening deposit requirements for its checking accounts. Over the past year, J.P. Morgan Chase & Co.'s Chase, Bank of America Corp. , and Wells Fargo & Co. have boosted the fees they charge noncustomers who use their automated teller machines to as much as $3 per transaction.

With all these changes, the average costs of checking-account fees, including ATM surcharges, bounced-check fees and monthly service fees have hit record highs, according to a new study by research firm Bankrate Inc.

Depositors are also paying more for extra services. In July, for example, Comerica Inc.'s Comerica Bank raised fees in Michigan for customers who want to stop payments or get a cashier's check. Last year, PNC Financial Services Group Inc.'s PNC Bank introduced a processing charge of $3 for customers who use their debit card to get a cash advance at a teller window.

Along with the tough economy and higher credit costs, another factor prompting banks to cut costs and raise fees and loan rates is a Federal Deposit Insurance Corp. proposal to increase the rates banks pay for deposit insurance starting next year in order to help replenish its reserves. If that rule change is approved, experts say, banks will probably pass on more of those higher costs to consumers by raising fees and boosting the minimum balances required to avoid fees.