* Piracy attacks worst since 2010 - Control Risks
* Gangs venture further afield, become more violent
* Oil gangs with powerful backers are prime suspects
By Joe Brock and Jonathan Saul
ABUJA/LONDON, Feb 21 (Reuters) - A spike in piracy offNigeria's oil-rich coast has shown gangs are willing to venturefurther afield and use more violent tactics, increasing the riskof doing business in Africa's largest energy producer.
Pirates demanded a 200 million naira ($1.3 million) ransomfor the release of six foreigners kidnapped on Sunday, thelatest in at least five attacks in Nigerian waters this month.
Exxon Mobil and Shell officials said thisweek that security was a major factor in Nigeria, and it was oneof the most expensive oil-producing countries to operate in.
"The recent upsurge in maritime kidnaps off the Niger Delta... has not been witnessed since 2010," said Roddy Barclay, WestAfrican analyst at Control Risks.
"It is easy to underestimate the debilitating effect such asituation can have, even on larger corporations," Barclay added.
Oil and shipping companies have to hire crisis managementteams, pay huge insurance premiums and face the prospect ofransom payments, as well as brace themselves for damage to theirreputations.
At the same time, pirates are becoming more ambitious.
Three crew members were kidnapped on Feb. 7 from theBritish-flagged cargo ship, Esther C, around 80 miles offshore,the furthest pirates have reached in the Gulf of Guinea.
Gunmen killed a Filipino crew member when they attacked achemical tanker three days earlier, in the first confirmed casein Nigerian waters of crew being killed on a vessel thatdeployed a private armed team, maritime risk experts AKE said.
OIL GANGS
The prime suspects for most attacks are Nigerian oil gangs,who already carry out industrial scale crude theft, called'bunkering' in the restive onshore Niger Delta swamplands.
Nigeria's oil minister said this week that oil theft, whichcan amount to 150,000 barrels per day (bpd), was the work of aninternational criminal syndicate. President Goodluck Jonathanhas reached out to Britain for help.
Security experts also believe Nigerian security officialsand politicians are complicit in oil theft and piracy.
"There are many top people in Nigeria involved incommissioning these attacks and sharing the profits," saidMichael Frodl, head of U.S. consultancy C-Level Maritime Risks.
"It's obvious to us that they've been bringing in people inother nations into the game, and sharing a cut in exchange fortips for tankers and cargoes."
Compounding the problem, there is less fuel available inNigeria since Jonathan reduced subsidies last year, which hasforced prices to rise. This has provided an added incentive forgangs to locally refine stolen oil or siphon fuel off ships theyattack, experts say.
The rise in pirate attacks comes as Nigerian forces havebeen more stretched in the last two years due to an Islamistinsurgency in the Muslim north.
"There is a sense that security resources are being focusedto combat the terrorist threat in the north of the country,"said Rory Lamrock, analyst with security firm AKE.
"We're likely to see further attacks over the coming monthsas local authorities are unable to effectively police thewaters, especially up to 50 or 60 nautical miles off the coast."
