European Community officials admitted today thay a shipment of 200 tons of uranium oxide lost on the high seas nine years ago was a European-owned stock in transit from Antwerp, Belgium, to Genosa, Italy.

While the officials would not comment publicly about reports that the material wound up in Israel, they privately indicated that this is indeed their understanding.

The officials are also alleging privately that the leak of the nine-year-old story in the American press was a deliberate tactic by U.S. officials to give substance to their current campaign to get Europeans to accept stricter international controls on the sale and transport of nuclear materials.

An EEC spokeman said today that Euratom, the Common Marjet's nuclear agency had conducted a "deep-going" investigation after the Euratom-controlled uranium disappeared.

Two top officials at the agency - its security director and its supply chief - resigned in late 1963 but the full results of the investigation were never published. The spokesman said that Euraton had tightened its control procedures since the incident.

One source here said that the jijacking of the uranium "is an exploit which more than matches the Cherboarg gunboats incident," referring to the daring Israel seizure of five gunboats from the Cherbourg harbor after France blocked their delivery to Israel under an arms embargo.

The story of the vanished unranium cargo and its rumored hijacking to Israel surfaced last week as the Carter administration prepared to press for legislation that would impose strict safeguards no nulcear exports.

"If the story was leaked, it was a dirty blow," one common market official said. "People are supposed to infer that since the unranium disappeared, terrorists will be able to steal our plutonium in the future."

Enriched unranium supplies to Europe have been blocked for several months while the United States reviewed its nuclear export policy. European leaders have complained that unless shipments are made, some nu- clear reactors may have to be shut down.

American officials have conducted a painstaking study of nuclear safeguards in foreign countries and have voiced concern about France's reluctance to sign the nuclear nonproliferation treaty. EEC experts argue that Euratom's controls are up to American standards and that licensing prohibitions on nuclear fuel exports should not reach the point of harming Europe's nuclear energy program.

While EEC Commission President Roy Jenkins received assurances last month from President Carter that supples will be resumed shortly, the delays have exacerbated European fears of vulnerability to outside fuel sources.

West Germany and France still hope to conclude lucrative sales of nuclear technology to Brazil and Pakistan, respectively.

Moreover, Europe and Japan intend to cut their dependence on foreign energy sources - oil from the Arabs and enriched uranium from the United States - by proceeding to develop fast breeder reactors fueled by plutonium, a move that is anathema to the Carter Administration's energy policy.

Plutonium, a highly lethal element, is derived from spent enriched uranium. When reprocessed, it can be used as a cheap, self-generating source of nuclear fuel that can be derived to weapons-making.

The tale of hijacked uranium EEC officials admit, will not help their campaign to convince the European public that nuclear programs can be safely implemented.

The slowdown in nuclear fuel supplies, which some EEC energy officials claim amounts to a virtual embargo, has increased Europe's incentive to deploy the plutonium-fed breeder reactors.

"If we stop developing the breeder, as President Carter suggests, we have to find and secure uranium sources," EEC Energy Commissioner Guido Brunner said in a recent interview. "But that means a greater balance of payments burden. Besides, our predictions show that there won't be enough uranium on the market to meet our needs a decade from now."

Europe's problems over enriched uranium shipments, coupled with growing public concern over the safety of nuclear power plants, have diminished its nuclear energy objectives.

Nuclear plants now provides 4 per cent of Europe's energy needs. The Common Market hoped to raise that proportion to 13 per cent by 1935, but now expects to reach no more than 8 per cent by then.