Interior Secretary Manuel Lujan has told a Senate panel the department has put a hold on efforts to turn over ownership of prime oil shale lands in Colorado and Utah to private mining claimants at $2.50 an acre.

Lujan's decision reverses one of the last major decisions of the Reagan administration's Interior Department, which announced in December that it would resume processing claims for as many as 240,000 acres in Colorado and Utah for a $2.50-an-acre filing fee.In response to questions from Senate Energy and Natural Resources Committee Chairman Bennett Johnston, D-La., Lujan submitted written testimony saying he will stop processing claims until the department develops new rules for determining if a claim is valid.

Lujan also said he will ask department lawyers to review a controversial legal finding by the previous administration. That decision allowed holders of mining claims to receive title to oil shale lands as long as they could show they are currently performing some work on the claim.

Critics contend the Mining Law of 1872 requires claimants to have conducted annual assessment work worth at least $100 every year since their claims were filed to be eligible to receive ownership of the land for the $2.50-an-acre filing fee. The claims involved in the dispute were filed before 1920, when the law was changed.

The Interior Department's position up to now has been that the resumption of assessment work is enough to qualify for ownership even if the claim was not worked for as many as 30 or 40 years before the work was resumed.

A number of conservative Western senators and congressmen have sided with Interior. They argue that mining claimants are entitled to ownership of the land under the mining law and to deny them that would amount to depriving them of their lawful property.

Sen. Tim Wirth, D-Colo., who has introduced a bill to halt claimants from getting the land at $2.50 an acre, said he was greatly encouraged by Lujan's statements.

"Secretary Lujan's response is a clear signal that the new Interior Department is pulling back the throttle on a full-steam-ahead approach to this giveaway," Wirth said.

No oil shale is being produced in commercial quantities anywhere in the country. Critics contend the mining law, which was designed to encourage development of the West's natural resources, is being used by land speculators to gain title to property that may some day be turned into vacation homes and resorts.

More than 80,000 acres in Western Colorado were turned over to claimants last year, some of whom immediately resold the land to oil companies at $2,000 an acre.