INDIAN OCEAN—Somali pirates hijacked the Greek-owned Maran Centaurus, a 1,085-foot supertanker hauling an estimated 2 million barrels of oil to New Orleans.

The vessel is covered by the Hellenic Mutual War Risks Assn. (Bermuda) Ltd., a spokesman for manager Thomas Miller (Bermuda) Ltd. confirmed. Protection and indemnity cover for the ship is provided through Arendal, Norway-based Assuranceforeningen Gard, sources said.

The Nov. 30 hijacking came just more than a year after Somali pirates seized the Saudi-flagged MV Sirius Star, the only other oil tanker pirates have successfully hijacked.

After that Nov. 17, 2008, hijacking, international authorities increased their naval presence in the Indian Ocean and established a safe travel corridor in the Gulf of Aden, an area near Somalia that leads to the Suez Canal. Since then, Somali pirates have moved their operations farther offshore. The Maran Centaurus hijacked Nov. 30 reportedly was 800 miles off the central Somali coast, a new distance record for Somali pirates.

The Maran Centaurus was the fourth successful hijacking by Somali pirates in November, after four successful seizures in October, according to the International Maritime Bureau's Piracy Reporting Center.

Somali pirates hijacked two ships from June through September—a period that roughly corresponds to monsoon season—according to the center.

Security experts said vessels that move slowly and have lower decks, such as oil tankers, are more vulnerable to pirate attacks.

Pirates anchored the Maran Centaurus off Hobyo, a village in northern Somalia. The ship's 28 crew members still were being held late last week, but were believed to be unharmed, media reports said.