Undated (AP) _ Iraqi warplanes blasted a fully loaded Turkish oil tanker with a rocket in the Persian Gulf today, but the vessel was able to sail on to Dubai, its owner reported in Istanbul.

Shipping sources in the Persian Gulf island nation of Bahrain also reported the attack, saying the vessel was believed to have been hit by a French-made Exocet missile.

Iraq announced that its warplanes had raided an unidentified ship near Iran's Kharg island oil terminal.

Kemal Sevindik, a spokesman for the Um Shipping Co., said in Istanbul, Turkey, that the Burak M was hit on the starboard side while sailing 78 miles south of Kharg Island. He said there were no casualties.

The sources, who spoke on condition of anonymity, said the vessel was ''not badly damaged.''

Company officials said the guided missiles had to have been fired by Iraqi jets because they are the only ones that have the capacity to launch night attacks. They also said it was considered unlikely that Iran would attack a ship carrying its own crude oil.

The 71,780-ton tanker had loaded 120,000 tons of crude oil from the island terminal and was on its way to a refinery at the Marmara Sea coast south of Istanbul, Sevindik said.

The tanker was heading for the United Arab Emirates port city of Dubai for repairs, Sevindik said.

Iraq has been using Exocet missiles to attack ships sailing to and from Iranian ports as part of its attempt to cut off vital Iranian oil exports and force a settlement to the Iran-Iraq war.

The sea-skimming missiles hit the targeted ships just above the waterline and therefore leave only a gaping hole in the side of the hull. The shipping sources said they cause minor damage unless they reach areas closer to the accommodation quarters.

An Iraqi military spokesman in the Iraqi capital, Baghdad, said the warplanes ''inflicted a direct and accurate hit'' on the target and returned safely to their bases.

In June 1984, another tanker of the Um Company, Buyuk Hun, was hit by Iraqi rocket fire near Kharg Island and three crew members were killed.

Iran is Turkey's major supplier of crude oil, providing 40 percent of an annual 12 million tons that Turkey imports.

The attack was the fifth such one to be announced by Iraq in eight days and the 67th since Jan. 1.

Independent shipping sources along the gulf have confirmed just 18 of those raids.

In April, Iraq announced twelve attacks on unidentified ships, but only the Cypriot-registered Kypros was confirmed to have been damaged, April 17 near Kharg Island.