NEW YORK, 12 June — Saudi Arabia said yesterday it has seized the ownership of an Iraqi crude oil pipeline that crosses its territory and has been shut down since Baghdad’s 1990 invasion of Kuwait.

In a letter to UN Secretary-General Kofi Annan, the Saudi Ambassador to the United Nations, Fawzi ibn Abdul Majeed Shubokshi, said Iraq’s threats of aggression had “destroyed any rationale” for maintaining the pipeline. The pipeline, “including the pipes themselves, the pumping stations, the storage tanks, the maritime terminal at Muejiz, the communications system and the loading facilities, will revert in its entirety to the government of Saudi Arabia with effect from the date of this letter,” he wrote. The letter was dated June 4 and released yesterday.

Shubokshi said “the just compensation due to the government of Iraq” for the expropriation should be deducted from Saudi Arabia’s claims against Iraq for damages resulting from the invasion of Kuwait. Shubokshi justified the Saudi decision by referring to a letter sent by Iraq to Annan in September last year.

Saudi Arabia said it was taking over the pipeline because Iraq had made threats against it and committed aggression, “thereby causing serious damage to the Saudi people in terms of lives and property, as well as to natural resources and the environment.” Because of this, Shubokshi said the pipeline “will revert in its entirety to the government of Saudi Arabia.” The seizure took effect last Thursday.

The Iraq-Saudi pipeline cost at least $2.25 billion to build and had the capacity to bring 1.6 million barrels per day to the Red Sea. It had been in full operation less than a year, from September 1989 until Aug. 13, 1990, alternately carrying Saudi and Iraqi crude to the Red Sea for export. A total of 876 million barrels of crude oil were exported via the pipeline.

Saudi Arabia disconnected the pipeline and blocked both ends after the UN Security Council imposed sanctions on Iraq for its invasion of Kuwait. Iraq last September asserted Saudi Arabia owed it unspecified damages for shutting down the pipeline.

But in the letter to Annan, Saudi Arabia said Iraq could deduct any damages from the money due Riyadh “for the damage resulting from the Iraqi aggression.” Sorting out the damage claims from the 1991 Gulf War is the work of the Geneva-based UN Compensation Commission.

Saudi Arabia last week accused Iraq of staging 11 raids on Saudi border outposts in March, April and May and warned the Security Council more such attacks could have “grave consequences.”

But Iraq’s UN Ambassador, Muhammad Aldouri, wrote Annan in a letter circulated yesterday that Saudi Arabia had fabricated the charges to build support for efforts by Britain and the United States to overhaul the UN sanctions on Iraq.

Washington and London hope to revise the UN oil-for-food program, an exception to the sanctions imposed on Iraq in 1990, by easing controls on civilian goods imported by Iraq while tightening restrictions on military-related supplies and clamping down on smuggling.

The program, renewed for one month last week in hopes new measures could be adopted by July 3, allows Iraq to sell oil and order food, medicine and other goods under UN supervision.