Secretary of Defense Caspar W. Weinberger has been pressing, so far unsuccessfully, for a new secrecy classification to cover technological and other kinds of information even if disclosure would not cause "damage to the national security."

A proposed new executive order under consideration at the White House has already generated controversy over the Cold War-era secrecy it dictates, but even the draft order falls short of Weinberger's desires.

Sources said Weinberger is expected to carry the issue to President Reagan in hopes of last-minute victory.

According to a copy of a memo obtained by The Washington Post, Weinberger advocated a new "security classification of 'RESTRICTED' "and said it was critical to "the effective safeguarding of a range of information that is not now generally classifiable."

The current security classifications--Top Secret, Secret and Confidential--have been in force since President Eisenhower's first year in office. The Reagan White House draft would require those labels for many more records than under existing rules, but the lowest level, Confidential, would still have a more rigorous definition than the Pentagon wants.

Under the Pentagon proposal, the Restricted stamp "shall be applied to information, the unauthorized disclosure of which reasonably could be expected to cause the loss to the United States of a technological, diplomatic, intelligence, cryptologic or military advantage and which requires protection in the interest of national security."

By contrast, the Confidential classification now in force can be applied only to documents whose unauthorized disclosure can reasonably be expected to cause "identifiable damage to the national security."

The White House draft would change that to eliminate the word, "identifiable," but "damage to the national security" would still be required for a document to be classified at all.

According to a two-page attachment to the Weinberger memo, dated Nov. 25, the only finding needed for a document to be Restricted would be "the loss of an advantage to the United States." In addition, such information would have to be kept secret under that heading if its disclosure "either by itself or in the context of other information" could be expected to cause that "loss of an advantage."

It is not clear whether the lost advantage would have to be governmental or commercial, and in competition with the Soviet Union or simply any foreign country or industry the classifying officer might have in mind.

Similarly, the notion of what might constitute a "diplomatic advantage" and how it could be lost is not spelled out.

The Defense Department contends, however, in one of the attachments to the Weinberger memo, that "There is a wide range of government information that currently is below the threshold of the criteria for classification but nonetheless requires a minimal degree of safeguarding.

"Valuable information, such as that pertaining to technology, especially critical technology with military application, diplomatic endeavors of the State Department, certain aspects of intelligence and crytologic activities and military operations, does not reach to the criteria for higher levels of classsification," the Pentagon rationale continues.

"Yet the loss of such information, and the advantage gained by our potential adversaries, demands that the government take steps to provide legal and positive control over it."

Weinberger also observed that "most of our NATO allies" use the Restricted classification. He said its usage here would relieve the Defense Department of the higher expenses of handling such material from NATO countries as if it were Confidential.

The Restricted classification has not been used in the United States since President Truman's administration, when it was defined simply as the lowest level of "classified security information."

President Eisenhower got rid of the category in 1953 and since then, according to a recent study by the privately funded Center for National Security Studies, each successive executive order has been issued "for the explicit purpose of reducing government secrecy . . . . "

The Reagan White House draft would reverse that trend, but the Weinberger memo, addressed to Steven Garfinkel, director of the executive branch's Information Security Oversight Office, argued that his department needed still more leeway "for the protection of information in the interest of national security."

The administration has already set off alarums in the scientific and academic communities as a result of CIA Deputy Director Bobby R. Inman's recent warning that scientists should submit to voluntary "reviews" of their work by U.S. intelligence agencies or face harsher action.

He has proposed a volunteer censorship system for research in such fields as "computer hardware and software, other electronic gear and techniques, lasers, crop projections and manufacturing procedures."

Weinberger's classification proposal was applauded by principal deputy assistant secretary for public affairs Benjamin Welles in a Dec. 11 memo.

He suggested it would obviate any need for a proposed exemption to the Freedom of Information Act concerning "technology which may be used for military purposes."