Lehman Brothers Inc. and Lehman Brothers International Europe (LBIE), its largest single customer claimant, announced the agreement in principle in a joint statement on Friday.

The accord requires approval by U.S. Bankruptcy Judge James Peck in Manhattan, which could come in the first quarter of 2013, as well as by the English High Court.

On Thursday, the U.S. brokerage unit announced a separate agreement with its former Swiss-based derivatives unit Lehman Brothers Finance AG.

Taken together, the agreements resolve two of the biggest outstanding claims facing the U.S. brokerage unit.

James Giddens, the trustee liquidating Lehman's brokerage unit, called Friday's accord a "critical milestone" that would let customers recover 100 percent of their property much sooner than if LBIE litigated claims over more than 200,000 trades.

Tony Lomas, joint administrator of LBIE, said under the accord he can focus on how to distribute more than $7 billion in assets.

Under the agreement, the European unit will be allowed $8 billion in claims for customer accounts. The accounts include $7.5 billion in securities and cash and $500 million in cash net equity.

The unit will also be entitled to a $4 billion general property claim, plus $600 million of "post-filing income."

Lehman Brothers Inc's $13.8 billion unsecured claim against the European unit will be eliminated. They will suspend litigation through mid-December while they craft a final accord.

Once Wall Street's fourth-largest investment bank, Lehman filed for Chapter 11 protection on Sept. 15, 2008. The filing was a major trigger of the global financial crisis, and Lehman's bankruptcy remains by far the largest in U.S. history.

Lehman emerged from Chapter 11 in March, and has paid out or plans to pay out $33 billion of an expected $65 billion to creditors, recovering an average of 21 cents on the dollar. The parent company is also being wound down.