Diamondback Capital Management, a hedge fund manager charged by the SEC last week in an insider trading scheme, has agreed to pay $9 million to settle the case.

The deal announced Monday, which also involves the Justice Department, spares the Connecticut firm from criminal prosecution.

The case illustrated the government’s practice of relying heavily on companies it is investigating to investigate themselves. In a news release, the Securities and Exchange Commission thanked Diamondback for doing much of the investigative work.

“In reaching the proposed settlement announced today,” the agency said, “the SEC considered the substantial cooperation that Diamondback provided, including conducting extensive interviews of staff, reviewing voluminous communications, analyzing complex trading patterns to determine suspicious trading activity, and presenting the results of its internal investigation to federal investigators.”

Under the settlement, Diamondback gave the government ammunition it can use in pursuing civil and criminal charges against former employees.

Diamondback agreed to a “statement of facts” in which it says a former analyst and a former portfolio manager at the firm obtained inside information about Dell, the computer maker, that was used to generate millions of dollars in illegal trading profits.

The case was another in a series asserting that hedge funds, the secretive and often lucrative investment vehicles, have been trading on inside information.

Monday’s settlement also illustrated a modest change the SEC recently announced to its long-standing policy of allowing defendants to settle cases with boilerplate language saying they neither admit nor deny wrongdoing.

With that approach under fire from a federal judge in New York, the agency recently said it will no longer allow defendants to use the no-admission language in SEC settlements if the defendants acknowledge wrongdoing in related settlements with the Justice Department.

Diamondback, which manages about $2.5 billion of assets, agreed to give up $5.2 million of ill-gotten gains plus about $833,000 in interest. It also agreed to pay a $3 million fine.

“We are gratified finally to have reached closure on the Government Proceedings, and deeply regret the difficulties caused to our investors during the last fourteen months,” Diamondback leaders Larry Sapanski and Rich Schimel said in a letter to clients Monday.