CHICAGO – Truly free checking accounts are becoming rarer as banks add more fees to boost their profits.

Only 39 percent of non-interest checking accounts are free to all customers, according to survey results released Monday by financial data publisher Bankrate.com. That's down from 45 percent last year and 76 percent in 2009.

Among other fees, the average monthly service fee on checking accounts is a record $5.48, up 25 percent from the Bankrate survey a year ago. Also, the average fee charged by an ATM operator to a non-customer rose 4 percent to a record $2.50, Bankrate said.