President Chadli Bendjedid has signaled his intention to use the first official visit to the United States by an Algerian head of state to purchase American military equipment in a move to lessen his country's dependence on the Soviet Union.

In an interview this past week, Bendjedid said he wanted to persuade the Reagan administration to give Algeria the possibility of buying sophisticated weapons on favorable terms. The president, who is to arrive in Washington on Tuesday, will be accompanied by a high-powered team of military and political advisers.

Bendjedid seemed at pains during the 100-minute interview to draw attention to his pragmatic stance both at home and abroad. His low-key approach provided a dramatic contrast with the espousal of dogmatic socialism at home and militant Third World causes abroad for which Algeria was known in the years following independence from France in 1962.

Western diplomats here view the president's five-day trip to the United States as a symbolic milestone in this country's gradual transition from a revolutionary socialist state to a nation seeking to redirect its primary energies to tackling long-neglected economic and social problems.

Bendjedid's visit already has aroused considerable interest, along with some misgivings, among Algeria's traditional diplomatic partners, especially the Soviet Union, its principal supplier of arms, and France, the former colonial power.

A senior Algerian official said his country sensed that an opportunity had arisen to gain Washington's attention in the wake of the controversial treaty of union signed last summer between two of its neighbors, Libya and Morocco. Bendjedid condemned the accord, which also aroused great suspicion in Washington, as an "unnatural" alliance between a revolutionary state and a conservative kingdom.

Among other points made by Bendjedid in the interview last Tuesday, his first with American journalists since taking power in 1979, were:

* The United States "can and should play a role" to help achieve a negotiated solution to the nine-year-old war in the former Spanish colony of Western Sahara that has pitted the Algerian-backed Polisario Front against Morocco.

* Algeria, fearful of further dividing the Arab world, has neither criticized nor approved the controversial agreement between King Hussein of Jordan and Palestine Liberation Organization Chairman Yasser Arafat on negotiations about the future of the Israeli-occupied West Bank.

* Along with other Third World countries, Algeria has in the past devoted too much attention to political and ideological questions. Bendjedid, who is spending part of his U.S. tour examining modern irrigation techniques in California's San Joaquin Valley, said Algeria needs to make a priority of agriculture, which now meets less than half the country's food needs.

Wearing a blue pinstripe suit and smoking almost continuously, the 56-year-old former guerrilla leader spoke alternately in Arabic and French during the interview, conducted in his spacious office in the presidential palace. Bendjedid's relaxed fireside manner and shock of white hair have gained him the nickname "Jeff Chandler" in Algeria, a reference to the American movie actor he resembles.

Algerian-U.S. ties, broken by Algeria at the time of the 1967 Middle East war, were restored in 1974, and Algeria later played a key role in the negotiations that led to the release by Iran of the Americans held hostage in Tehran.

Noting that Algeria in the past has been accused of excessive military dependence on Soviet Bloc countries, Bendjedid said he wanted to find out whether "a political will" exists in Washington to sell his country military equipment.

"We have no complexes; we will buy arms in both East and West," he said. "If there is the political will on the part of the U.S. to sell arms to Algeria, then our specialists will make proposals."

Although Bendjedid denied that Algeria had a specific shopping list, senior Algerian sources said it was interested in modernizing its Air Force and acquiring U.S. radar and electronic equipment. Bendjedid is being accompanied by Kamal Abderrahim, the armed forces deputy chief of staff, and the head of the Defense Ministry's foreign procurement department.

"We are looking for a breakthrough," a senior Algerian official said, explaining that President Reagan's personal authorization is required before Algeria can buy offensive military equipment from the United States under the terms of the Foreign Military Sales Act. Algerian and U.S. officials say they expect Washington to announce that approval this week.

Until now, Algerian purchases of U.S. military equipment have been limited to such "nonlethal" items as 17 C130 Hercules transport planes. Ever since its eight-year struggle for independence against France, Algeria has acquired 80 to 90 percent of its arms from the Soviet Bloc, although some recent purchases have been made from France, West Germany and Britain.

Bendjedid implicitly linked the diversification of the country's arms supplies to its status as a nonaligned state by insisting that he was prepared to do business with any country "that respects our sovereignty and independence."

According to western diplomats here, the number of Soviet military advisers attached to the Algerian armed forces has dropped from a high of around 3,000 to about 1,200. Bendjedid said that the reduction in Soviet military personnel stationed here could be expected to continue as Algerians mastered foreign weapons systems.

Western analysts here said any U.S. arms sales to Algeria would upset neighboring Morocco, with which the United States traditionally has maintained much closer political and military ties. Morocco has used U.S. military equipment in the war in Western Sahara, which it annexed in 1975.

Bendjedid accused Morocco of "closing the door" on a negotiated solution to the Sahara dispute by rebuffing a series of Algerian initiatives in recent months. He said he "did not understand" what he depicted as frequent changes of course by King Hassan II on terms for a political settlement.

"We are disappointed by Morocco's response because we feel that Morocco thinks there can be a military solution to this conflict. We do not believe that," he said.

Both Moroccan and Algerian officials have confirmed that Bendjedid offered a deal to Hassan last year under which Western Sahara would have become an autonomous region of Morocco. The proposal appeared to fit Hassan's declared readiness to consider any compromise short of "the postage stamp and the flag" but was rejected by Morocco on the ground that it might eventually lead to full independence for the territory.

Bendjedid said he wanted Washington to play a role in resolving the conflict even though he did not expect the solution "to come directly from the U.S." A senior official later explained that Algeria would like the Reagan administration, as a first step, to encourage further direct talks between Morocco and the Polisario Front.

While insisting that Algeria had never interfered in Morocco's domestic politics, Bendjedid speculated that internal Moroccan reasons could lie behind what he depicted as a recent toughening in Hassan's public position on the Sahara. He said opposition parties in Morocco recently had been making "demagogic statements" about the war.

An Algerian diplomat said the hardening in Rabat's position had followed last year's treaty between Morocco and Libya, adding that Libyan leader Muammar Qaddafi could have encouraged Hassan to take a hard line.

Whether true or not, the comment appeared to be a sign that Algerian officials would like to turn the Reagan administration's dislike of Qaddafi to their own advantage.

Bendjedid described Qaddafi as the enfant terrible of the region but said he was opposed to any foreign intervention in Libya to get rid of him.

In discussing the Middle East, where Algeria long has sought to play a major role, Bendjedid gave the impression of fence-sitting. This caution apparently was dictated by a desire to avoid repetition of Algeria's awkward backing of the ill-fated Israeli-Lebanese withdrawal agreement in 1983, which fell apart as a result of Syrian-led opposition.

He appeared to criticize the agreement reached between Jordan and Arafat in Amman on Feb. 11 by saying that "we don't really believe in partial solutions" such as those proposed in the Camp David agreements that eventually led to a separate peace between Egypt and Israel. He also said the Hussein-Arafat agreement involved only "a part of the Palestinians."

He went on to insist, however, that he could not give a "correct analysis" and was adamant that Algerian participation last month in a Syrian-led meeting in Damascus of radical states in no way signaled Algeria's open opposition to the Amman agreement.

That meeting, Bendjedid said, "did not study or analyze" the Jordanian-Palestinian agreement. Algerian officials claimed that their presence in Damascus effectively had prevented Syria from using the forum to condemn the Hussein-Arafat initiative.

Officials here claimed that Algeria participated in the Damascus meeting to prevent a further split between moderate and radical Arabs before Bendjedid's visit to Washington. Bendjedid follows Saudi King Fahd and Egyptian President Hosni Mubarak to Washington and is expected to be followed by Hussein.

Bendjedid indicated that he was not about to resume diplomatic ties with Egypt, which were interrupted after the peace agreement with Israel. He said, "We are not in agreement on political policy, but that does not prevent us from having good relations" with the Egyptian people.

Resumption of diplomatic ties with Egypt, he said, was a decision that could be made only by a summit of "all Arab countries," a formulation that in effect allows Syria or any other radical state to exercise a veto.

On the issue of long-overdue domestic reforms, Bendjedid acknowledged that Algeria had a lot to learn from the United States in what have now become priority areas for the economy. He said these included agriculture, irrigation and housing construction.

"My policy is based on pragmatism rather than dogmatism. I want to be close to the needs of our people, their basic aspirations," he said, adding that the "happiness of the individual" had now become the watchword in Algeria.

He described as "a very positive development" a decision by the Organization of African Unity to devote its summit in July to tackling the continent's staggering economic problems, such as famine and drought.

"This shows that Africa is more interested in economic problems than ideological and political problems," he said, adding that African nations should strive to become "self-reliant" rather than relying on outside aid.