The Carter administration, under pressure from the Saudi Arabian government, is reassessing its two-year-old investigation of alleged price-fixing by domestic and foreign oil companies in the Middle East.

Although government officials insist that the Justice Department probe is continuing on schedule, requests for sensitive financial information about the operations of Aramco -- a Saudi-dominated consortium that includes several American oil firms -- may be dropped, sources said.

The decision rests with Attorney General Benjamin R. Civiletti, but in previous cases of this type, the White House has had the final say.

The State Department already has recommended that parts of the investigation offensive to the Saudis be dropped. The Saudis are unhappy because information they consider private is being sought in the probe. Several Justice and Energy Department officials said withdrawing the requests for information effectively would abort the investigation.

Saudi objections were stated in the strongest terms in a private conversation between Saudi Oil Minister Sheik Ahmed Zaki Yamani and U.S. Treasury Secretary G. William Miller during Miller's Middle East trip two weeks ago, according to sources familiar with their meeting.

The objections from Saudi Arabia, which has been America's most trusted oil-producing friend in the tumultuous Mideast, come at a time when Iranian oil to the United States has been cut off and Libya has threatened a cutoff.

According to one senior administration official, Yamani "pounded his fist on the table, and was especially persistent" in seeking Miller's help in pulling the Justice Department off the investigation.

Other administration sources, who have seen copies of a cable from U.S. officials in Saudi Arabia to Secretary of State Cyrus R. Vance describing the conversation, say Yamani threatened some sort of retaliatory action if the U.S. investigation were not curtailed. sThe sources said, however, that Yamani did not cite specific actions.

The officials said that Yamani particularly is irked by Civil Investigative Demands (CIDs), subpoena-like requests from the Justice Department, that have been sent to the four U.S. partners in Aramco -- Texaco, Standard Oil of California, Exxon and Mobil.

The CIDs request otherwise private information about Saudi Arabia, the fifth partner in Aramco, and its priceing practices.

The sources said Yamani argued that it is unfair, in light of his and his country's friendship and cooperation with the United States, that his country should be the target of such an investigation, which could lead to his embarrassment.

Yamani and Saudi Arabia have long endured criticism from the rest of the Arab world for their friendly stance toward the United States, and he is reported to be afraid that any information made public about the Saudi-U.S. relationship will be used against the Saudis and himself.

Saudi Arabia is the largest crude oil supplier to the United States, providing an estimated 1.4 million barrels a day out of total imports of nearly 8 million barrels a day.

Yamani also has argued, as have the governments of many other countries, that the United States has no right to subpoena financial information about foreign countries.

Energy Department sources say the Saudis were angered several months ago when the Senate Foreign Relations Committee made public some information about Saudi pricing practices that it received by subpoena from two of the Aramco companies.

At that time, the sources said, Yamani penalized the two companies involved by supplying them with 20,000 barrels a day less oil than it supplied the two other companies for the rest of 1979.

In addition to Justice, the departments of State, Treasury and Energy are being consulted about Yamani's most recent complaint. Officials would not say if Treasury or Energy have made their recommendations.

The Justice Department investigation, opened in 1977, is focusing on the activities of multinational oil companies doing business in the Persian Gulf, and on whether U.S. antitrust laws have been violated in the pricing arrangements worked out there.

Acting Associate Attorney General John Shenefield, who leads the antitrust division, told the Senate Judiciary Commitee last week that no other federal investigation "rises to the level of importance" of the international oil probe.

Shenefield said that the antitrust division has been involved in talks with the departments of State and Energy and also said there "was cable traffic about the Department of Treasury trip to the Middle East."

But Shenefield said he could not talk about the cables because their contents were classified. "I can't very well talk about it without violating criminal law," Shenefield said.

Shenefield said the State Department "has warned of the potential difficulties that might be caused by the investigation," but he added that the antitrust division issued two sets of CIDs anyway.

He maintained that "nothing has happened to cause me to believe" that the investigation will not be completed by spring.

But several middle-level officials working on the Justice Department case said their work is at a standstill while the complaint raised by Yamani and passed on by Miller is being resolved.

As Justice spokesman would say only that the department had "received a report of a meeting between Miller and Sheik Yamani through normal State Department cable traffic." The spokesman would not comment further "because the traffic is classified," he said.

This is not the first time a foreign government has challenged the government's international oil probe.

In 1977, the British government, reacting to the first set of CIDs, issued an order barring two British companies -- British Petroleum Co. and a British subsidiary of Shell Oil Co. -- from complying with Justice Department requests for information.

A British official, however, said that the Justice Department has been "fairly persistent" in trying to work out ways to get the information.

Shenefield acknowledged that the first set of requests for information had met resistance.

"As far as I am aware, the response by the American oil companies to the first set of CIDs was wholly responsive," he said. "Foreign companies have not been as responsive."