* Shell, Total, Eni own stake in Nigeria LNG
* NLNG says it is exempt from shipping levies
* Nigeria accounts for 7 pct of global LNG supply
By Joe Brock
ABUJA, June 27 (Reuters) - Nigeria's liquefied natural gas(LNG) exports have been blocked for a sixth day by the maritimesecurity agency due to a dispute over shipping levies, the stateLNG firm said on Thursday.
Nigeria ships around 330 cargoes a year, providing about 7percent of global LNG supply and accounting for 4 percent of GDPin Africa's second largest economy, state-LNG company NLNG says.
Since June 21, the Nigerian Maritime Administration andSafety Agency (NIMASA) has barred LNG cargoes from entering orleaving the loading bay because it says NLNG is not paying alevy of three percent on product value.
"If they want us to pay a levy it needs to be passed intolaw by government. We abide by the law," Nigeria LNG spokesmanKudo Eresia-Eke said.
"Under the Nigeria LNG act we are exempt from shippinglevies," Eresia-Eke said, adding he did not know when exportswould resume or how many cargoes had been delayed.
NIMASA did not immediately respond to a request for comment.
The security agency blocked exports on May 3 before NLNGagreed to pay it $20 million to resume flows while it went tocourt to dispute the blockade, NLNG said.
NLNG says a court order was issued on June 18 preventingNIMASA from blockading the port until a resolution was found.
The Nigerian National Petroleum Corporation owns 49 percentof NLNG with Shell holding 25.6 percent, Total 15 percent and Eni 10.4 percent.
Buyers of Nigeria's LNG include Spain's Repsol,Italy's Enel, Britain's BG Group France's GDFSuez and Portugal's Galp.