The trustee Irving Picard, who is liquidating Bernard L. Madoff Investment Securities and recouping money for former customers, also agreed with Ruth Madoff that the accord is not evidence she admitted to "participating in or knowing of Bernard Madoff's fraud," court papers show.

According to settlement papers, Ruth Madoff, 77, who was never charged in connection with her husband's Ponzi scheme, will pay $250,000 in cash and give up $344,000 of trusts for two grandchildren.

Ruth Madoff, the wife of imprisoned swindler Bernard Madoff, agreed to pay $594,000 and surrender her remaining assets when she dies to settle claims by the court-appointed trustee liquidating her husband's firm.

She is cooperating with Picard in ongoing recovery efforts, according to the settlement agreement release. Her attorney Peter Chavkin had no comment on the settlement, when reached by CNBC.

Ruth Madoff's settlement was made public on Friday, and requires approval by U.S. Bankruptcy Judge Stuart Bernstein in Manhattan. Peter Chavkin, a lawyer for Madoff, declined to comment on Monday.

In June 2009, shortly before Bernard Madoff was sentenced to 150 years in prison, prosecutors reached an agreement with the Madoffs allowing federal marshals to sell their assets, while permitting Ruth Madoff to keep $2.5 million.

Picard had sought $44.8 million from Ruth Madoff, but in a court filing called her settlement a "fair and reasonable compromise," citing her limited assets and the litigation risks.

In June 2017, Picard reached settlements of more than $23 million with the estates of the Madoffs' late sons, Mark and Andrew, and related defendants.

Mark Madoff committed suicide in December 2010 at age 46. Andrew Madoff died of cancer in September 2014 at age 48.

Bernard Madoff, 81, was arrested in December 2008 and pleaded guilty three months later.

— CNBC contributed reporting.

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