Like a high-powered real estate firm, the Reagan administration yesterday opened its drive to unload the property it doesn't need, complete with plans to set sales targets and offer potential buyers installment plans.

President Reagan established a White House-level Property Review Board and Budget Director David A. Stockman gave property-owning agencies 60 days to notify the board of the land and buildings they no longer need.

Testifying before the Senate Governmental Affairs Committee, Stockman said the board would establish annual target levels of property disposal for each agency. Just over half of the sales, he said, would be from properties managed by the General Services Administration or controlled by the Defense Department. The remainder are lands managed by the Interior and Agriculture Departments and the Corps of Engineers.

The administration hopes to raise $2.2 billion in fiscal 1983 and $4 billion a year after that, by selling surplus buildings and land and changing its policies on donating property. Stockman said the actual sales prices would be much higher than that, but it expects to take in that much each year by allowing purchasers to pay by the installment plan at prevailing rates over a period of time.

About half the projected revenues would come from administrative changes that Reagan has already made, including eliminating the practice of transferring properties to other governments and nonprofit groups for free or for a low price.

Stockman said he would ask private real estate agents to promote the sales to help cut down the four to six years it usually takes between the time a property is declared surplus and when it is sold.

He added that legislation would be submitted in March to rewrite laws that now limit the property sales. Chief among them is the Land and Water Conservation Act, which specifies that property sale revenues must purchase parklands.

Named as members of the property board were Stockman, White House Counselor Edwin Meese III, Council of Economic Advisers Chairman Murray L. Weidenbaum and national security adviser William P. Clark. Other members will be named later.

During the hearing, Stockman discounted a plan advanced by Rep. Ken Kramer (R-Colo.) to offer some of the land through government loans at a 10 percent interest rate.

"Financing at these rates can have an extremely important psychological effect in this country," said Kramer, who along with Rep. Larry Winn Jr. (R-Kan.), has sponsored a measure calling for a nationwide federal property inventory.

Kramer's measure, however, would channel a percentage of the profits into improving remaining federal properties and would bar corporations and individuals from unlimited purchases.

"We can earn not only billions upon billions of dollars, but we can make a significant attempt to pay off the entire national debt with these sales," Kramer said. The debt, however, now totals $1.049 trillion, well above the expected revenues.

Sen. Charles H. Percy (R-Ill.), who chaired the hearing, urged the administration to focus on the Defense Department's surplus and recreational properties. Percy illustrated his point with pictures of Fort DeRussy, a 72-acre DOD property on Waikiki Beach, Hawaii, with a luxury hotel that serves vacationing military personnel at reduced rates.

"These properties are in the attic and we're going to move them down to the garage and conduct a garage sale," he added.

Percy, Stockman and Kramer repeatedly said that environmentally sensitive holdings and national parklands would not be sold.