President Reagan for the first time has authorized systematic Defense Department review of high-technology exports to noncommunist countries, settling a bitter administration dispute and giving security concerns more prominence in trade policy, administration officials said yesterday.

The decision was contained in a classified memo signed by White House national security affairs adviser Robert C. McFarlane eight days ago and sent to the secretaries of state, defense and commerce, officials said.

Reagan intervened after the Commerce and Defense departments failed to reach agreement on their own despite more than two years of wrangling.

The directive allows the Pentagon to review all commercial applications for licenses to export certain types of equipment to 15 noncommunist countries, from which the Defense Department has said it fears that the equipment could be reshipped to the Soviet Union.

Exports that will come under Pentagon jurisdiction include computer parts, scientific instruments and other equipment that Defense Department officials believe could have military application.

The long-running dispute reflects a wider disagreement between the constituencies that the two departments tend to represent, administration officials said. Defense Department officials have been most concerned with what they see as a hemorrhage of valuable western technology to the Soviet Union, while Commerce Department officials have worried that the Pentagon would delay and impede harmless trade, injuring the position of U.S. companies in the world market.

Pentagon officials said yesterday that they view the presidential directive as a major victory.

"It means that a long impasse has come to an end," one official said. "It means that the security concerns expressed by the Department of Defense from the earliest days of the administration will now be given greater weight. And hopefully it means an end to a dispute between the two departments that has resulted in too many licenses being granted without review by the Department of Defense and too many questionable ones being granted overall," the official said.

Commerce Department officials said, however, that they are satisfied with the mechanisms for review and appeal created in the presidential decision.

"They wanted the lead on the whole thing, but at best they come out equal," one official said. "We don't see this as a win or a loss for anybody."

The presidential directive formalizes, with some revisions, a draft memo of understanding that Reagan approved last March, thinking that would settle the issue. Departmental wrangling continued, however, and the draft memo was never signed.

The directive allows the Pentagon to tap into the Commerce Department computer to review information collected about specific license applications. Some business representatives have opposed this.

"We will now have the benefit of all the information available to Commerce, which during this period they have refused to make available to us," a Defense Department official said. "The Commerce Department is instructed to throw the switch on an automatic data-processing system linking the two departments."

The Pentagon must object within 15 days after an application is filed if it wishes to halt an export, a provision intended to allay business anxieties.

If Commerce Department officials do not share Pentagon concerns about a specific license, the matter is to be resolved by a committee on which Donald R. Fortier, deputy national security affairs adviser, would cast the deciding vote.

Either Cabinet secretary could appeal the committee decision to the president, according to officials familiar with the directive.

Other committee members will be Richard N. Perle, assistant secretary of defense for international security policy who has taken the lead in seeking increased Pentagon authority; the assistant secretary of commerce for trade administration, when that position is filled, and, on some issues, a nonvoting State Department official.

Defense Department officials said they also could review "distribution licenses," which permit exportation of an entire category of goods to several countries.

The Pentagon also could reshape the list of 15 countries as circumstances change.