American Express will reimburse $85 million to about 250,000 customers to resolve accusations that the company violated federal law in its marketing, billing and debt collection practices, the company and the government said Monday.


The settlement is the latest in a series of enforcement actions that federal and state regulators have brought against some of the nation’s largest financial institutions for problems in their credit card businesses.


The multiagency investigation of American Express included the Consumer Financial Protection Bureau, the Office of the Comptroller of the Currency and the Utah Department of Financial Institutions. They discovered problems in three American Express subsidiaries between 2003 and 2012 that ranged from the way the company advertised its cards to how it pursued customers behind on their bills.


The violations of consumer protection laws started “from the moment a consumer shopped for a card to the moment the consumer got a phone call about long overdue debt,” Richard Cordray, the director of the consumer protection bureau, said in a statement.


To win customers for its “Blue Sky” travel reward credit card program, the lender sometimes offered them a $300 reward, which never materialized, the regulators said. In doling out credit, they said, American Express also discriminated against applicants based on their age. The company also duped consumers into paying off stale credit card debt with the promise of improving their credit score, the investigators said; in fact, regulators found, American Express was not reporting the payments to the credit bureaus at all.


The three subsidiaries involved in the agreement are American Express Centurion Bank, American Express Travel Related Services Company, and American Express Bank FSB.


American Express customers should expect refunds by March 2013, regulators said. The company also agreed to pay $27.5 million in fines to the regulators.


American Express, long known for its aspirational cards and tonier customer base, said it had outlined plans to address each of the violations and “cooperated fully” with regulators.


Under the deal with regulators, the company must halt the deceptive practices and set up independent auditors to ensure that its practices comply with consumer protection laws.


The fines and customer refunds will be paid, for the most part, by reserves established in prior quarters, American Express said.


“Separately, the company is continuing its own internal reviews and is also cooperating with regulators in their ongoing regulatory examination of add-on products in accordance with an industrywide review,” American Express said in its statement.


The move against the bank is part of a broader push by federal and state regulators to protect consumers from illegal credit card and debt collection practices as millions of Americans struggle to pay their bills in a floundering economy.


So far this year, the newly minted Consumer Financial Protection Bureau has leveled enforcement actions against Capital One and Discover Financial over sales tactics of credit products. Last week’s action against Discover resulted in the company agreeing to pay $200 million to more than 3.5 million cardholders who bought credit protection services over the phone, plus an additional $14 million in civil penalties to banking regulators.


Monday’s enforcement action was “intended as a message to all entities,” said Kent Markus, assistant director of enforcement for the consumer bureau. “There are consequences for violating the law.”