The Securities and Exchange Commission has modified its controversial policy of letting defendants settle cases without admitting or denying wrongdoing — but the change is so narrow and applies under such limited circumstances that one critic denounced it as “less than meaningless.”

Until now, the SEC has condoned a contradiction. Defendants could plead guilty to criminal charges or be convicted of them and still settle related SEC civil cases by stating that they neither admit nor deny the agency’s charges.

That’s ending.

Companies and other defendants found guilty in criminal proceedings will no longer be able to settle parallel SEC actions with the standard provision saying the defendant neither admits nor denies the charges, the SEC said Friday.

In the affected cases, defendants still will be prohibited from denying the allegations, but they won’t be required to admit wrongdoing. They can remain silent on that point.

For all other cases, the SEC has left intact its general policy of settling cases with boilerplate clauses stating that the defendants neither admit nor deny wrongdoing.

In a statement Friday, SEC enforcement director Robert Khuzami said that the change was adopted last week after a review that began last spring.

The old approach “reflected that the goals, objectives and other factors in the civil settlements that we and other federal and state agencies enter into often are distinguishable from those at issue in criminal proceedings,” Khuzami said.

“It nevertheless seemed unnecessary for there to be a ‘neither admit’ provision in those cases where a defendant had been criminally convicted of conduct that formed the basis of” the SEC action, he said.

The change was first reported by the New York Times.

The SEC’s old approach was “indefensible” and the change is “less than meaningless,” Dennis Kelleher, president of the advocacy group Better Markets, said in a statement.

The only benefit of the change, Kelleher said in an interview, is that it “eliminates the SEC looking foolish in such settlements.”

The SEC often files lawsuits or administrative actions against the same parties targeted by the Justice Department, partly because the SEC has the authority to make sure that fines go to the victims.

A December bid-rigging case against Wachovia highlighted the disconnect.

The Justice Department issued a news release headlined: “Wachovia Bank N.A. Admits to Anticompetitive Conduct by Former Employees in the Municipal Bond Investments Market and Agrees to Pay $148 Million to Federal and State Agencies.”

The SEC was one of those agencies. “Without admitting or denying the allegations in the SEC’s complaint,” the SEC’s news release said, Wachovia had settled the SEC’s piece of the case by agreeing to pay $46 million.

The SEC is responsible for policing Wall Street and making sure that publicly traded companies issue proper financial disclosures for investors. The agency pursues cases such as insider trading, accounting fraud and corporate bribery of foreign officials.

The agency has long settled cases with a standard disclaimer that the defendant neither admits nor denies wrongdoing. That enables the SEC to claim victory and the defendant to put the matter to rest without the type of formal legal concession that could be used against the defendant in private lawsuits by injured parties.

The practice has come under fire by a federal judge in New York, Jed S. Rakoff, who says it leaves the allegations unproven and can make the appropriateness of the penalties impossible to assess.

Here “an agency of the United States is saying, in effect, ‘Although we claim that these defendants have done terrible things, they refuse to admit it and we do not propose to prove it, but will simply resort to gagging their right to deny it,’ ” he wrote.

In a March 2011 opinion, Rakoff criticized an SEC settlement involving accounting fraud at Vitesse Semiconductor, saying that two executives settling with the SEC on the standard terms had already pleaded guilty to parallel criminal charges.

Ironically, the absence of an admission to the SEC’s charges was less of a problem under those circumstances, Rakoff wrote. Given the guilty pleas, “The public is not left to speculate about the truth of the essential charges,” he wrote. In November, Rakoff rejected the SEC’s proposal to settle a fraud case against Citigroup for $285 million. The agency has appealed.

The SEC says many defendants would refuse to settle if they had to admit wrongdoing. As a result, the SEC says, it would have to pursue cases all the way to a trial verdict, tying up money and manpower that would better be devoted to other investigations.