A plan to chip at national debt by selling surplus lands; Capitol Hill could call for reassessment of properties, sale of nonessential land

You couldn't quite call it a National Tag Sale, but the idea is the same. A plan gaining favor on Capitol Hill these days would have Uncle Sam sell off his excess assets so that the funds could be used to put a dent in the nation's trillion-dollar debt. Lawmakers who support the idea see a revenue bonanza in the sale of surplus government property.

The federal government is the single largest real estate holder in the country with more than 700 million acres under its control. The government's real property holdings are valued at $130 billion, including 415 parcels listed at $1.3 bilion that have been declared surplus.

Sen. Charles H. Percy (R) of Illinois has introduced a resolution that would direct the President to inventory all federal assets, determine which are surplus, and recommend to Congress ways of providing for proper sale of the surplus assets. The resolution would exclude national parks, monuments, and historical sites from the inventory.

At the heart of the liquidation drive is the belief that the $1.3 billion figure is far below the actual value of the surplus property. That dollar amount is based on the acquisition cost of the property - acquisitions that in some cases took place decades ago. For budgetary reasons, the General Services Administration (GSA), which disposes of the surplus property, only reassesses the value of holdings that are about to be sold.

Supporters of the resolution are quick to point out examples of undervalued lands in government hands. They include property on Nantucket Island listed at $ 35 an acre (though the least expensive acre on the resort island currently sells for around $30,000 per acre), federal lands in Nevada on the books at 65 cents an acre, and property in Illinois at $300 an acre.

''In times like this when we are asking for sacrifices from so many, we owe it to the American taxpayer to sell excess property at full market value,'' says Senator Percy. ''The federal government may have at its disposal a major new source of revenue that may ultimately reduce the burden of the national debt.''

Tying funds from future sales of surplus property to retirement of the national debt is a key concern, says an aide to Rep. Larry Wynn Jr., who has introduced an identical resolution on the House side. ''If the money was used simply to balance the budget, all we'd be doing, in effect, is selling an asset to pay for a short-term note,'' says the aide.

But such a move may create political problems. At present, revenue derived from the sale of surplus property is deposited in the Land and Water Conservation Fund, where it is used to buy and develop national parkland. Since the Land and Water Conservation fund has recently been the object of a pitched battle between environmentalists and the Interior Department, some fear that any plan to divert additional money from the fund would be fiercely contested.

Sponsors of the resolution believe that much more surplus property would surface if government agencies were given incentives to identify their unessential assets. Experts argue that without incentives some agencies might oppose the resolution because it would force them to dispose of excess land that they want, but don't really need.

The Reagan administration is generally in favor of the resolution. The President himself has indicated support for the concept, and presidential counselor Edwin Meese III commented favorably on the plan in a recent speech.

A spokesman at the Office of Management and Budget says that at ''the highest levels of the administration'' an ''intensive study is under way with a strongly sympathetic view toward the principles involved.''

But the administration's views may not entirely dovetail with those of the sponsors of the resolution. While agreeing that revenues for surplus land sales should not go into the Land and Water Conservation Fund, the administration is not entirely committed to using the revenue solely for the purposes of retiring the national debt.

Also, the administration has no desire to undertake a costly new inventory of government property, though the identification of surplus assets lies at the very heart of the Senate resolution.

A property liquidation expert at the GSA concurs with the administration's position. ''The Senator is proposing activities of staggering magnitude,'' he says, arguing that a new piece of legislation will not automatically eliminate legal and political obstacles that are usually attributed to GSA policies.

The current system of surplus property sales is not conducive to streamlining says the official, citing inherent delays such as environmental litigation and the pleadings of congressmen and other officials not to sell particular properties.

Other opposition to the plan may come from owners of property that borders on surplus government landholdings. Inevitably, huge land sales would have a deflationary effect on the value of nearby property. Nevertheless, the National Realtors Association recently endorsed the resolution, concluding that any plan that could reduce the national debt - and thus lower interest rates - warrants consideration.