The Consumer Financial Protection Bureau on Thursday sought to bring debt collectors and credit bureaus under its purview, marking the first time the often controversial industries would be subject to federal supervision.

Under its proposed rule, the CFPB would oversee the nation’s largest debt collectors, the primary credit reporting agencies such as Experian, Equifax and TransUnion, and other lesser-known consumer reporting agencies. It is the first attempt by the watchdog agency to define which businesses in the vast swath of nontraditional financial institutions will be subject to the same examination process as banks.

“This oversight would help restore confidence that the federal government is standing beside the American consumer,” CFPB Director Richard Cordray said in a statement.

Cordray said a reason why they are targeting these firms is because they have expanded their reach into consumers’ lives during the recession. More people are now being pursued by debt collectors and have watched their credit scores slip.

Those scores have become crucial in the aftermath of the financial crisis. Some employers are even looking at credit scores as criteria for jobs. A car, a home, a college education are all financed by lenders that rely on the score to determine who gets credit and how much they pay for it.

For most consumers, those scores are based on records of loans they have taken out in the past and how well they have paid them off. This information is housed in the Big Three national credit bureaus — Experian, Equifax and TransUnion. Lenders use formulas developed by companies such as FICO and VantageScore to analyze the data and determine how likely each person is to repay.

Government regulators, financial firms and consumer advocates have launched extensive education campaigns in recent years to make sure that consumers understand what goes into their Big Three credit reports and how that affects the cost of a loan.

But little attention has been paid to the so-called “Fourth Bureau” firms that target the 30 million consumers outside the mainstream financial system. Often they are students, immigrants or low-income consumers who do not qualify for traditional loans or choose not to use them. Instead, they rely on a makeshift system of payday lenders, check cashers and prepaid cards — none of which show up in the Big Three. Without a paper trail of credit, these consumers are virtually shut out of the traditional banking system.

As a result, fourth bureau firms are increasingly using non-traditional and, at times, unreliable data, including auto warranties, cellphone bills and magazine subscriptions to come up with credit scores.

Yet federal regulations do not always require these companies to disclose when they share your financial history or with whom, and there is no way to opt out when they do. No one is even tracking the accuracy of these reports. That has left the most vulnerable consumers with little insight into the forces determining their financial futures.

The CFPB agency became the first federal agency to oversee so-called “nonbanks” after President Obama appointed Cordray as director late last year. But before it can use its power, the CFPB must set standards for which companies make the cut.

The proposed rule sets the bar for debt collection agencies at $10 million in annual receipts. The CFPB estimated that would encompass about 175 firms that account for about 63 percent of the debt collected from consumers each year.

For consumer reporting agencies, the CFPB proposed a standard of $7 million in annual receipts. That includes not only the three major credit bureaus but also roughly 30 smaller firms in the Fourth Bureau. The rule would give the CFPB authority over about 94 percent of the industry by receipts.

The power to oversee such firms and other nonbanks was a key component of the new agency’s design, and the CFPB has quickly flexed its muscle. It has already convened hearings on payday lending and plans to propose new rules for mortgage servicers.

The agency said it will continue to roll out guidelines employing a variety of criteria to define businesses that will be subject to supervision.

“This is going to be a very important way for us to interact with industry participants to know exactly what they’re doing,” Cordray said. He added that the power could be more efficient than using the “blunt instrument of lawsuits.”