* Biggest ever ransom paid for Greek-flagged tanker
* Oil tanker has 2 million barrels of oil onboard
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By Mohamed Ahmed and Abdi Guled
MOGADISHU, Jan 17 (Reuters) - The largest ransom ever paid to Somali pirates was dropped on Sunday onto a Greek-flagged oil tanker with two million barrels of oil on board, pirates and maritime officials said.
An aircraft dropped a ransom believed to be between $5.5 million and $7 million for the release of the tanker which was hijacked near the Indian Ocean archipelago of the Seychelles, the officials said.
The Maran Centaurus was seized on Nov. 29 with nine Greeks, two Ukrainians, one Romanian and 16 Filipinos on board and the ransom dwarfs amounts paid previously for vessels held captive by Somali sea gangs.
The tanker has yet to be freed as a dispute between rival pirate gangs over the spoils means the recipients are wary of returning to the coastal haven of Haradheere with their booty.
“The problem is now that the pirates on the vessel will not be able to return to the shore, because of the infighting. At present there is a stand-off and nobody can predict how the release will develop,” said Ecoterra International, a Nairobi-based group that monitors shipping off Somalia.
Earlier on Sunday, pirates aboard the tanker and rivals in speedboats fired at each other in a tussle for control of the vessel before the ransom was due to be delivered.
Pirates aboard a hijacked ship nearby and local elders onshore told Reuters helicopters from Western navies patrolling the waters off Somalia fired at the speedboats, clearing them from the area before the cash was dropped.
A $3 million ransom was paid for the release of another oil tanker, the Sirius Star, in January 2009. Ransoms around that figure have been paid subsequently for the release of merchant shipping vessels.
Ransom negotiators and middlemen have become expert at depositing large amounts of cash on vessels. The ransom paid for the Sirius Star 2009 floated down onto the deck in an orange canister suspended from a parachute.
The pirates in the speedboats had threatened to set the tanker ablaze if they did not receive a share of the spoils.
“We have risked our lives in hijacking the ship. These Haradheere men cannot deprive us of our rights,” a pirate called Aden told Reuters. “If need be, we shall start a fire as soon as the ransom is about to arrive.”
Somali pirates had a bumper year in 2009. Worldwide piracy attacks surged nearly 40 percent, with Somali pirates accounting for more than half of the 406 reported incidents, according to the International Maritime Bureau (IMB).
Typically, the pirates hold the ships and crew hostage until they are paid ransoms and free the vessels. With ransom payments running into millions of dollars, the stakes are high for the gunmen in their poor, anarchic Horn of Africa nation.
At the end of last year, Somali pirates were holding at least 12 vessels for ransom with 263 crew members of various nationalities as hostages, the IMB said last week.
Ransoms are usually divided between the hijackers — with bigger shares going to those who first boarded the vessel — people who have invested in the pirate ventures, those who guard moored ships and local communities onshore.
There is even a small pirate “stock exchange” in Haradheere where Somalis can contribute money or weapons to the sea gangs in return for a dividend when ransoms are paid. (Additional reporting by Abdi Sheikh in Mogadishu and David Clarke in Nairobi; writing by David Clarke; editing by Myra MacDonald)