A broad coalition of advocacy groups is calling on the Securities and Exchange Commission to press ahead with an expansion of a fiduciary standard to hold broker-dealers to identical standards of care for retail client that are already imposed on investment advisors.

In a letter to SEC Chairman Mary Jo White dated June 4, the groups, which include the Investment Adviser Association and the Certified Financial Planner Board of Standards, urged against a watered-down fiduciary standard for broker-dealers, and expressed concern about the tack the agency might be taking following its recent call for more information from the public.

In March, the SEC issued a request for information asking for more input from industry members and other stakeholders about the potential impact of a uniform fiduciary standard, particularly with regard to the anticipated costs and benefits of such a rule.

In their joint letter, the groups praised the SEC for soliciting more information, but said that they are "very concerned" about several elements of the proposal, "despite the RFI's caution to readers that the various assumptions contained in it should not be construed as the staff position."

"We certainly hope that this is the case, because the assumptions contained in the RFI fail to include key elements of the fiduciary standard, such as the obligation to act in the best interest of the customer," the groups wrote in their letter.

The groups said that their support for a uniform fiduciary standard is conditioned on a rule that would be "no less stringent" than the current standard to which advisors are held. A more lax fiduciary rule designed for broker-dealers, if applied as the uniform standard the SEC envisions, could have the perverse effect of lowering the standard of care advisors are currently required to exhibit when providing their retail clients with personalized investment advice.

They also said that they appreciate that any rule the SEC issues should account for the nuances of the broker-dealer practice.

"We maintain that the fiduciary duty standard should be supported by guidance to clarify how the standard would apply to the broker-dealer business model and rules where needed," the groups wrote. "We believe that such an approach, if properly implemented, could both enhance investor protections and preserve key beneficial elements of the transaction-based broker-dealer business model."

Opponents of the uniform standard have warned against rules that could erase the distinctions between the broker-dealer and advisory practices. SEC officials have countered that a uniform standard is a critical investor protection at a time when there is considerable overlap in the services provided by financial professionals of both designations and significant confusion among retail investors about the various standards of care to which each is held.

White has said little about the SEC's uniform fiduciary proceeding since taking over at the SEC in April. At her confirmation hearing the previous month, she promised a thorough review of all the comments the SEC is collecting on the issue, and, more generally, to move quickly on a variety of the open proceedings that have been lingering at the agency.

In addition to the IAA and CFP Board, the groups asking the SEC this week for a strong uniform fiduciary standard were the AARP, The American Institute of CPAs, the Consumer Federation of America, the Financial Planning Association, Fund Democracy, the National Association of Personal Financial Advisors and the North American Securities Administrators Association.

Copies of the letter were delivered to the other SEC commissioners and the bipartisan leaders of the relevant congressional committees.