A Michigan law firm has agreed to pay a $131,000 fine to resolve an investigation into donations to former Sen. John Edwards' 2004 presidential campaign.

The Federal Election Commission said Thursday it had reached an agreement with the law firm of Geoffrey Fieger, who once represented assisted suicide advocate Dr. Jack Kevorkian, after the commission found probable cause that Fieger's firm violated campaign finance laws.

Fieger, a Democrat who lost a bid for Michigan governor in 1998 against Republican Gov. John Engler, has denied any wrongdoing.

Fieger and his law partner, Ven Johnson, were acquitted in 2008 of illegally funneling campaign money for Edwards' 2004 presidential race. Jurors said the government failed to prove the lawyer knew he was breaking the law.

Fieger's lawyer, Michael Dezsi, said the firm decided to pay the fine instead of continuing the litigation. "We felt confident that we would have prevailed as we did against the Justice Department. But for the amount we were able to negotiate the settlement, it simply just wasn't worth the litigation. We've spent years litigating this," he said.

Under the agreement, which was reached in October, the FEC said it found probable cause that the law firm made payments to 66 individuals to reimburse them for $131,000 in contributions to Edwards' presidential campaign. Under campaign finance laws, corporations are barred from making contributions to a candidate and donors are prohibited from contributing in the name of another person.

The commission voted to take no further action against Fieger or Johnson. Documents filed by the commission show that FEC commissioners were deadlocked over whether Fieger and Johnson "knowingly and willfully" violated campaign finance laws. Deszi said that finding could have led to fines of about $1 million.