Adds detail, background and company statement from paragraph 2

MOSCOW, July 20 (Reuters) - The Caspian Pipeline Consortium, which exports oil mainly from Kazakhstan, said on Monday that it has again suspended loadings after a brief resumption, following a new Ukrainian drone attack on a tanker.

Ukraine and Russia have stepped up attacks on vessels and other facilities in the Black Sea and the Sea of Azov in recent weeks, trying to undermine each other's war efforts.

The closure of the pipeline, which exports almost 2% of global oil, is likely to heighten uncertainty on global oil markets that are already rattled by the war in Iran and closure of the Strait of Hormuz, a key waterway for crude.

CPC, whose shareholders include U.S. majors Chevron CVX.N and Exxon Mobil XOM.N, said in a statement that a drone attacked a tanker called NELSA, which was loaded at one of two single-point moorings.

A fire broke out on the deck and in the compartments of the tanker after it was struck on the starboard side. The crew and emergency teams subsequently put out the fire.

The international crew of 22 was evacuated aboard CPC tugboats, with the exception of the captain and chief officer. The tanker remained afloat.

"Oil loading operations were suspended. No oil spill occurred and no ignition of oil in the cargo tanks was allowed," CPC said.

The CPC is a 940-mile (1,510 km) oil pipeline connecting Kazakhstan's Caspian Sea oil deposits with Russia's Black Sea port of Novorossiysk. Oil loaded at Novorossiysk is then taken by tanker to world markets. CPC accounts for about 80% of Kazakhstan's oil exports.

It had initially suspended oil loadings when two oil tankers were attacked at its terminal near Novorossiysk, then briefly resumed them before the attack on the NELSA.

Kazakhstan's energy ministry said at the time that the single-point mooring facilities, SPM-1 and SPM-3, were not damaged.

CPC reduced oil supplies in June by 7% from May to 6.442 million metric tons, or 1.699 million barrels per day, according to the sources, due to an accident at the Tengiz oilfield in late May and lower volumes of Russian crude.