Capital One, one of the nation’s biggest banks, will reimburse $150 million to more than two million customers for selling them credit card products they could not use or did not want, as the nation’s new consumer watchdog leveled its first enforcement action against the financial industry.

The Consumer Financial Protection Bureau on Wednesday hit Capital One with findings that a vendor working for the bank had pressured and deceived card holders into buying products presented as a way to protect them from identity theft and hardships like unemployment or disability.

The regulatory actions, totaling $210 million including fines to authorities, take aim at one of the financial industry’s growing profit centers and increasingly controversial practices. Several other banks, including Bank of America, JPMorgan Chase and HSBC, were sued in June by the Hawaii attorney general, accused of improperly selling similar so-called add-on products, which consumer advocates typically regard as costly and ineffective.

Related Links Documents: The news release

“We know these deceptive marketing tactics for credit card add-on products are not unique to a single institution,” said Richard Cordray, the director of the consumer bureau. “We expect announcements about other institutions as our ongoing work continues to unfold.”

Capital One — known for its catchy television ads that ask, “What’s in your wallet?” — did not admit to or deny any of the findings. While it said the wrongdoing had occurred at outside call centers that “did not always adhere to company sales scripts,” the bank’s president for credit cards, Ryan M. Schneider, acknowledged that the company was “accountable for the actions that vendors take on our behalf.”

“We apologize to those customers who were impacted and we are committed to making it right,” Mr. Schneider said.

Under the deal with regulators, Capital One must temporarily halt the marketing of certain add-on products and submit to an independent audit. The bank said it thought the refunds, which victims are to begin receiving later this year, would average less than $100 a person.

In a related action, the Office of the Comptroller of the Currency required the bank to reimburse customers “harmed by unfair billing practices” that unfolded over a 10-year span, from 2002 to June of last year. The bank, regulators say, billed customers even though it had failed to provide full use of the product.

“Unfair and deceptive practices will not be tolerated,” Thomas J. Curry, the comptroller, said on Wednesday.

The regulatory scrutiny comes on the heels of several Wall Street blowups and federal investigations that have stoked the anger of consumers and investors. Last month, Barclays agreed to pay authorities $450 million to settle accusations that it had manipulated a benchmark interest rate, part of a wide-ranging inquiry. JPMorgan Chase is dealing with the fallout from a multibillion-dollar trading debacle.

The Capital One action was the consumer bureau’s first effort at flexing its enforcement muscle. A centerpiece of the Dodd-Frank regulatory overhaul law passed in response to the 2008 financial crisis, the two-year-old bureau is charged with rooting out abuses in areas including mortgages and payday loans.

The action Wednesday suggests that the enforcement arm is emerging as a cornerstone of the agency, which early on faced skepticism over whether it would aggressively police the nation’s biggest banks. Mr. Cordray, who previously ran the bureau’s enforcement division, said that his agency’s investigations would now happen “more steadily.”

What is more, the enforcement action will most likely embolden consumers to file class-action lawsuits, according to Stacie E. McGinn, a lawyer at Simpson Thacher & Bartlett in New York. “This practice is hardly limited to Capital One,” said Richard Golomb, a lawyer in Philadelphia who has brought class-action lawsuits against lenders for payment protection insurance.

That product, which promises to forgive or trim the debts of card holders in the event that they lose their jobs, become disabled or die, became particularly attractive to anxious consumers in the depths of the recession. While costs vary by card issuer, companies typically charge up to 80 cents for every $100 of debt that is insured, lawyers for consumers said.

In addition to deceptively pushing those plans, regulators say, Capital One offered credit monitoring, a feature that came with identity-theft protection and “credit education” for customers with a spotty borrowing history.

In a 30-page order, the consumer bureau outlined how call centers for the bank marketed and sold the products to ineligible unemployed consumers and forced the products without the consumer’s consent. In other cases, according to the bureau, the bank employed “high pressure tactics,” including misleading customers into thinking the product was free, mandatory and would bolster credit scores.

The bank has run afoul of regulators before. In January, Attorney General Darrell V. McGraw Jr. of West Virginia, reached a $13.5 million agreement with Capital One to settle accusations surrounding its payment protection programs.

The attorney general of Mississippi, Jim Hood, also sued Capital One in June for reportedly “slamming” customers by enrolling them in payment protection programs without their consent and then hitting them with fees.

A top official at the industry trade group the American Bankers Association, Kenneth Clayton, said that for some people “the value of the product is worth the cost. People buy these products for a number of reasons, including peace of mind and knowing they will be protected if certain untimely life events make it difficult to repay their bills.”

Capital One, in contrast, has tussled with consumer advocacy groups like the National Community Reinvestment Coalition, which has assailed the bank for its subprime and risky lending. About a third of Capital One’s credit card portfolio carries the subprime label, defined as loans to borrowers with credit scores below 660, the company said last year.

The coalition led the charge last year against Capital One’s bid to take over ING’s online banking unit in the United States, saying the deal would create the next too-big-to-fail banking behemoth. The deal, the latest in a string of acquisitions, transformed Capital One into the fifth-largest bank by deposits. Capital One on Wednesday reported that its second-quarter profit dropped 90 percent to $92 million, because of the bank’s recent acquisitions.

While the Federal Reserve approved the ING deal, the consent came with some crucial conditions. The Fed, citing consumer complaints and legal actions against the bank, ordered Capital One to bolster its internal controls of lending and debt-collection practices.

In addition to David M. Louie, Hawaii’s attorney general, suing seven major banks over what were suspected to be unfair and deceptive sales of credit card add-ons, the Minnesota attorney general, Lori Swanson, sued Discover in June 2010, accusing the credit card company of duping consumers into buying the products.

Jill Amundson, who manages real-estate holdings in Minneapolis, said she was shocked when charges for payment protection insurance started showing up on her Discover card bill in 2008. “I never enrolled and I find it particularly galling because the charges are small so you might miss them,” she said. Discover waived the charges once she complained.

A spokeswoman for Discover said the company takes “every customer’s concerns seriously” and tries to address them.