Besides its vast oil wealth, Iran has reserves of another key energy source destined to become increasingly valuable in the future: uranium.

Iranian and Western nuclear energy experts confirm the existence of the reserves in Iran, but say their size and whether they can be commercially exploited at current uranium prices remain to be determined.

"They look promising, there's no doubt about that," an Iranian official said of the uranium anomalies discovered so far. Anomalies are indications of mineral content in rock based on magnetic readings. According to officials, some of the geological formations in which the anomalies have been found are similar to the richest in the United States.

(The United States has the world's largest known reserves of uranium, estimated at 277,000 short tons of U308, according to the U.S. Nuclear Regulatory Commission.)

To ascertain the size and quality of its reserves, Iran is launching one of the most ambitious uranium exploration programs ever undertaken, Iranian officials said. The government has budgeted $300 million for the program over the next 10 years and the first phase - three years of "airborne prospecting" - is due to start by early May, they said.

Iran, the second largest oil producer in the Organization of Petroleum Exporting Countries, wants to be a supplier of uranium to fuel nuclear power stations after its oil runs out in about 20 years.

As an energy exporter, "our policy and our ambition is to sit on the same side of the table as we are sitting right now," said Ghassem Arabyan, head of the uranium exploration division in the Atomic Energy Organization of Iran.

To achieve this goal, Iran is seeking joint ventures in foreign countries and is negotiating such agreements with Niger, Gabon and Zambia, Arabyan said. No foreign participation will be allowed in domestic uranium ventures, however.

As part of a plan to stockpile uranium until its own production gets well under way, Iran has already purchased 30,000 tons of uranium from foreign sources, with deliveries starting this year and lasting until 1994.Iranian officials are keeping any projections of domestic uranium production close to the vest, but a paper presented at a nuclear technology conference in Iran this month, cited agreements to purchase 30,000 tons of uranium concentrates from the 40,000 tons required up to 1990 - implying that Iran expects to produce 10,000 tons itself. Western officials said this was a conservative estimate.

Iran plans to install about 20 nuclear power stations to generate some 23,000 megawatts of electricity by the early 1990s. Two stations have been ordered from West Germany and two more are being negotiated with France.

The air surveys will be carried out by three firms - Australian, West Germany and French - under contract to the Atomic Energy Organization. The surveys will concentrate on a hilly strip of land along Iran's eastern border and the Azerbaijan area in the northwest, officials said.