HELENA, Mont. (AP) – A federal judge has given preliminary approval to a $3.4 billion settlement for Native Americans who say the government mismanaged their land royalties, paving the way to begin a search for hundreds of thousands of potential beneficiaries.

U.S. District Judge Thomas Hogan of Washington, D.C., made his decision Dec. 21 and ordered the formal beneficiary notification period to begin in 30 days, or Jan. 20.

Congress approved the class-action settlement earlier this month after nearly 15 years of litigation over the royalties from property owned by Indians and held in trust by the government.

The Department of Interior leases the land to others for farming or resource development and is supposed to pay the money generated by the land into Individual Indian Money trust accounts.

But money that was supposed to go into Indians' accounts was squandered, stolen and mismanaged for more than a century, the plaintiffs alleged.

Attorneys for the lawsuit's lead plaintiff, Elouise Cobell of Browning, Mont., say the number of potential beneficiaries could reach 600,000. But the government has correct names and addresses for only half that number, the plaintiffs said.

Two companies, Kinsella Media and The Garden City Group, have been hired to carry out the search using $20 million from the settlement, plaintiffs attorney Dennis Gingold said in a statement Dec. 22.

Hogan tentatively set June 20 as the date for a fairness hearing on the plan to disburse the settlement money.

The plaintiffs have said the first checks won't be sent to plaintiffs until at least August, and the complete disbursement could take six more months after that.

The judge named J.P. Morgan Chase & Co. as the qualifying bank to handle the disbursement. He also set an April 20 deadline for individual Indian beneficiaries to opt out of the class-action settlement and pursue their own claim with the government.