SunTrust Banks Inc. and Regions Financial Corp. said they will stop charging customers for making purchases with debit cards, marking the latest banking-industry retreat from a monthly fee that drew an outraged response from customers.

The announcements follow decisions last week by Wells Fargo & Co. and J.P. Morgan Chase & Co. to drop customer tests of the new fees. Together, the four banks operate around 15,000 U.S. branches, while controlling more than $2.2 trillion in deposits and $1.6 trillion in loans—more than 20% of the industry total.

The about-face by the four big banks represents a rare concession to customer sensitivities over lucrative fees. Hit hard by a soft economy and tightening regulations, banks have been adding fees on services, charging for instance for many checking accounts that used to be free.

But none of those moves appears to have generated the intense response of the debit-card charge.

"Consumers have clearly said this is a no-go," said Patricia Hewitt, who specializes in debit cards at Mercator Advisory Group Inc. in Maynard, Mass.