eading OPEC oil ministers sought today to reassure world markets, and themselves, that no oil war of competition within the cartel would result from its failure yesterday to agree on a new pricing and output structure.

"I don't think our failure to reach an agreement will result in a disaster, either in terms of prices or production," said Kuwait's Oil Minister Ali Khalifa Sabah, one of those who had been at the center of frustrated efforts to forge a compromise among the embittered factions of the Organization of Petroleum Exporting Countries. "I hope any ill side effects will be limited."

Sabah and other OPEC ministers said they expected that the 13 member nations would adhere, more or less, to the output quotas and pricing schedules that were in effect before this weekend's extraordinary meeting. Such adherence, by preventing price-cutting and other competition for market shares, would help to hold the reference price for OPEC oil at $34 a barrel.

But several ministers hedged statements to reporters about their own plans, warning that if other producers tried to cut prices to attract buyers and raise production, they would do the same.

The organization appeared, in effect, to be taking a calculated risk that the exercise of self-restraint by individual members and a forecast of strengthened world demand for oil in coming weeks would hold the floor for the price of OPEC oil until the cartel can find a new formula for unity.

Beneath the surface of calm assurances that OPEC will survive and prosper, however, strong economic and political pressures are acting to reshape power relationships in the cartel.

Iran, which emerged here to challenge what had been Saudi Arabia's dominance over OPEC during the past two years, has been primarily reponsible for derailing the previous agreement. Needing cash to finance its war with Iraq, Iran has produced oil well above its assigned level and cut its prices to sell it.

There were indications that Saudi Arabia, OPEC's largest producer, might be considering lowering its prices after it was unable here to relieve pressure that is making it more difficult to sell its oil. The Saudis failed to get Iran to stop offering discounts or to persuade African producers to raise prices on some of their crudes and thus make Saudi oil more competitive.

Mana Said Oteiba, the oil minister of the United Arab Emirates and the head of OPEC's market-monitoring committee, said today that a possible drop in the Saudi price was one of the matters likely to come up in talks he is having soon with Saudi officials.

"You cannot expect the Saudis to see their production declining sharply because they haven't been able to sell, where there are other member countries who are giving all kinds of discounts," Oteiba said. Saudi Arabia's output in June was reportedly 6.5 million barrels a day, compared with its OPEC quota of 7 million.

Saudi Arabia was largely responsible for establishing the cartel's $34 benchmark price last October. But Saudi Deputy Oil Minister Abdul Aziz Turki did not rule out a change in the price of the Saudis' Arab light crude.

"Probably it will remain [the same]; I don't know," the Saudi official told reporters late last night. "Saudi Arabia will monitor the market and decide." He said his country would protect the sales of its Arab light crude "as it deems necessary."

The Iranians warned the Saudis against trying to engineer a glut and pressure other members. Iran's oil minister, Mohammed Gharazi, said his country would also do anything to defend its recently increased share of OPEC production--"even if it has to resort to force."

The reference to force, Gharazi later explained when asked, was meant purely in commercial terms.

Given the heightened uncertainty around the oil market, Venezuela, which had threatened to raise its own output if a workable quota system were not adopted, said it would take a wait-and-see approach.

"I think most of the countries have the intention to remain where we are," said Venezuelan Oil Minister Humberto Calderon Berti. He said Venezuela would maintain its price and production levels but added that this was conditional on others respecting the collective ceiling on OPEC production of 17.5 million barrels per day set in March.

Ministers acknowledged last week that OPEC is already producing above that level, at around 18.2 million barrels per day. But organization members appeared willing in this interim period to continue to tolerate some leakage.

Responsibility for calling another ministerial meeting to decide on a new OPEC output and pricing plan has been left to the organization's four-nation monitoring committee, which is due to meet here Aug. 24.

Several ministers said that resolution of OPEC's overproduction and pricing problems is likely to become easier once the demand for oil tightens. They said they expect this to happen over the summer as the drawdown in corporate oil inventories reverses itelf and companies begin restocking for the winter.

But this is not certain to happen. The world demand for OPEC oil has fallen as a result of recession and successful conservation measures as well as dumping of oil companies' inventories on markets. Doubt about the continuing effect of these factors in keeping the oil market soft contributed to last night's decision to suspend the OPEC conference to study the market further.

The central internal problem facing OPEC--and the main issue over which the ministers' talks broke down last night--is how to accommodate the economic recovery of Iran and its growing oil sales. Further down the line, Iraq is expected to present a parallel problem. The oil output of both countries was depressed for several years as a result of revolution in Iran and the war between the two countries.

At the meeting, there reportedly was general agreement that Iran's quota had been set too low three month ago. Gharazi said he had been offered a new quota of 2.5 million barrels per day, substantially above the previous 1.2 million. Iran is currently producing about 2.2 milllion barrels a day.

But the deal failed, Gharazi said, because Saudi Arabia refused to make room for the Iranian increase by reducing its own quota, as the Iranian minister had insisted.

Iran is trying to resume the major position it held in OPEC under the shah, before its production declined and it assumed a secondary status in the cartel. Saudi Arabia's share of total OPEC output grew--as did its power within OPEC--as Iranian output fell.

"Getting back Iran's share," Gharazi said, "should come from those who grabbed it at the occasion of Iran's revolution and promised to give it back very explicitly in the records of OPEC. This means it should be reduced from Saudi Arabia and nobody else."

Gharazi, noting that total OPEC production has been cut in half since its peak in 1979, said production shares of individual members within the cartel should be only half of what they were then. This would give the Saudis a level of 5 million barrels per day and Iran 3 million, he said.

Gharazi said output shares in OPEC should be based on historical shares and other "logical criteria" such as national financial needs.