WASHINGTON — Fidelity Investments, BlackRock Inc. and PIMCO are battling efforts by regulators to consider labeling asset management firms as systemically important.

The three asset management companies were among more than two dozen firms, industry stakeholders and lawyers that filed letters in an effort to discount the credibility of a report released by the Office of Financial Research in October.

"The conclusions in the report are based on a number of inaccurate assumptions about how asset managers, including institutional asset managers, operate, the report should not be relied upon by the council in its review of the asset management industry," wrote Douglas Hodge, managing director, chief operating officer of Pacific Investment Management Company LLC. "PIMCO urges the SEC, as a member of the council, to recommend that the council revise and re-issue the report and not use the report as a basis of future policymaking."

The Securities and Exchange Commission invited the industry to weigh in on the report, which was intended to examine whether asset management firms that oversee $53 trillion in financial assets could pose a systemic risk to the economy.

"We often provide opportunity for public comment on reports on topics of interest to the Commission [and] its staff," said John Nester, a SEC spokesman.

He did not provide any further details on how the agency plans to use the comment letters it has received.

Under the Dodd-Frank Act, the Financial Stability Oversight Council has the authority to identify companies it believes pose a risk to the system. Those firms face a host of tougher regulatory requirements and automatically fall under the Federal Reserve Board's supervision.

The council, a 10-member regulatory panel led by Treasury Secretary Jacob Lew, has already designated three non-bank firms — American International Group, GE Capital and Prudential Inc. — and that list is likely to grow.

The FSOC had asked the Office of Financial Research, which acts as a data arm of the regulatory council, to examine the risks posed by large asset managers. In its report, the OFR said such companies are susceptible to various vulnerabilities like "reaching for yield" and "herding."

Regulators are concerned that firms in a low-interest rate environment may try to seek higher returns by buying up riskier assets or that asset managers would crowd into similar or even the same assets simultaneously.

The FSOC held an initial discussion a few weeks after the report was delivered by the OFR, according to a read-out from a Oct. 31 meeting. Treasury spokeswoman Suzanne Elio declined to comment on the possible designation of asset management firms.

Mary Miller, undersecretary of domestic finance for the Treasury Department, said the intent of the report was to improve the council's understanding of the asset management industry and figure out whether there are risks that could be transmitted to the broader financial system.

"I would want to emphasize that this is still early days," said Miller at the Bloomberg State & Municipal Finance Conference on Wednesday. "I think that it is incumbent on the FSOC to understand asset managers."

Even so, firms like Fidelity, BlackRock, and others are already building their case against the report.

In a letter to regulators, Scott Goebel, Fidelity's general counsel, criticized the report as an "incomplete, inaccurate and misleading view of the industry" that should not be relied upon as the basis for future regulatory recommendations.

The Boston-based firm, which manages $1.7 trillion in client assets, claimed there were a number of flaws with the report, including its failure to include certain significant market participants and industry segments in its review. Fidelity also criticized the report's failure to distinguish between the myriad of asset management firms, activities and markets that make up the industry.

PIMCO, which manages $1.97 trillion in assets, also disputed OFR's assessment, arguing that it presented an inaccurate reflection of practices by institutional asset managers. The firm also said the report failed to show the substantial amount of valuable industry-related data or the regulatory landscape where such data is reported and collected.

Other firms, including Fidelity, also cited OFR's inability to back up its claims.

"The OFR fails to provide sufficient data or analysis to support any of the speculation included in the report, which we find striking given that the OFR has described itself as 'focused purely on research, data, and analysis,'" wrote Goebel.

David Oestreicher, chief legal counsel for T. Rowe Price Associates Inc., said the agency's report lacked the "necessary rigor" and was ultimately "inconclusive due to its emphasis on anecdotal claims and a scarcity of supporting data."

The OFR has previously openly acknowledged its shortcoming in its data collection, saying that with better information it would have been able to draw stronger conclusions.

In a statement, a Treasury spokesperson said the 34-page report by the OFR was meant as a "brief overview of the industry and analysis of how asset management firms and the activities in which they engage can introduce vulnerabilities that could pose, amplify, or transmit threats to financial stability."

Companies also told regulators that while certain risks associated with investment products should be addressed by policymakers, asset management firms by themselves do not pose systemic risk.

Barbara Novick, BlackRock's vice chairman, made the case that asset managers do not act as "lenders or counterparties" and maintain "very small balance sheets," especially compared to banks and insurance companies.

"The resolution of an asset management firm would not require government support," wrote Novick. "Indeed, asset management firm do not 'fail' in this sense, because they have no balance sheet activities to support."

Instead, asset management firms argued that all potential risks could be addressed with existing statutory authority. They said any regulatory reform effort would be better left to their existing supervisor, the SEC.

"If any further steps are taken by the FSOC, it is important that the FSOC collaborate with the SEC and other regulators with relevant subject matter expertise to collect and understand available data about capital market and asset management industry risks," wrote Timothy Cameron, managing director of the asset management group for the Securities Industry and Financial Markets Association in a joint letter with the Investment Adviser Association.

Donna Borak is the Federal Reserve reporter for American Banker.