WASHINGTON - The Federal Reserve adopted rules Tuesday aimed at protecting credit-card customers from getting socked by hefty late-payment charges and other penalty fees.

The rules, effective Aug. 22, respond to public and congressional outrage over some practices by the industry.

Key provisions bar credit-card companies from:

Charging a penalty fee of more than $25 for paying a bill late.

Charging penalty fees that are higher than the dollar amount associated with a customer's violation.

Imposing "inactivity" fees when customers don't use the account to make new purchases.

Charging multiple penalty fees on a single late payment.

"Consumers will finally be protected from the worst credit-card issuer abuses," said Rep. Carolyn Maloney (D., N.Y.), a major advocate for the changes.

In addition, the rules require companies to reconsider interest rates imposed on customers since the start of 2009. Some lenders pushed through rate increases ahead of the first phase of sweeping new credit-card protections, which took effect this year. Those rules were designed to protect customers from sudden hikes in interest rates.

Congress directed the Fed to implement the new credit-card protections in legislation signed into law by President Obama last year.

"The new rules require that late payment and other penalty fees be assessed in a way that is fairer and generally less costly for consumers," said Fed Governor Elizabeth Duke, the central bank's point person on the rules. "Card issuers must also reevaluate recent interest rate increases, and, if appropriate, reduce the rate," she added.

The American Bankers Association said the industry intended to "work quickly and diligently" to implement the new provisions.

Legislation in Congress revamping the nation's overall financial regulatory structure could reduce the Federal Reserve's influence over consumer protections.

A Senate-passed bill would house a watchdog agency inside the Fed, but chairman Ben S. Bernanke would have no authority over it. A House-passed bill would set up a separate agency devoted to consumer protection and would strip the Fed of some of its consumer oversight.

Lawmakers are working to reconcile the bills into a final package.