UPDATE 4-Nigerian rebels attack oil facility, eye offshore

* Militants attack Chevron oil station in Niger Delta

* Fifth attack claimed against U.S. oil major in a month

* MEND threatens to sabotage offshore oilfields

(Updates with military comment)

By Randy Fabi

ABUJA, June 15 (Reuters) - Nigeria's main militant group on Monday threatened to extend its attacks to offshore oil facilities after sabotaging a Chevron-operated oil pumping station in the Niger Delta.

The Movement for the Emancipation of the Niger Delta (MEND) said it attacked the Abiteye flow station early on Monday, the fifth militant attack claimed against the U.S. energy company in Delta state in less than a month.

The military confirmed the attack, but said its security forces were able to secure the facility and force the retreat of dozens of suspected militants.

"The hoodlums were overpowered by our troops and forced to flee," said Colonel Rabe Abubakar, spokesman for the military task force in the Niger Delta.

The U.S. oil major has already shut down its operations around Delta state after MEND's first pipeline attack on May 24, halting about 100,000 barrels per day of oil output in Africa's biggest oil and gas producer.

Oil markets have largely shrugged off the latest violence, focusing attention instead on the broader global economy and its effect on energy demand.

MEND, responsible for attacks that have cut one fifth of Nigeria's oil production in the last three years, threatened to begin sabotaging oil facilities outside Delta state, including offshore oil fields.

"HURRICANE WILL MOVE"

"After destroying the entire oil infrastructure in Delta state, the hurricane will move into the neighbouring states of Bayelsa and Rivers before passing through the remaining states of Ondo, Edo and Akwa Ibom then finally head offshore," MEND said in an e-mailed statement.

MEND last June carried out a raid on Royal Dutch Shell's Bonga oil platform, the Anglo-Dutch giant's main offshore facility 120 km (75 miles) from the coast, forcing the firm to temporarily stop the $3.6 billion site.

But a year later, security experts say MEND has been weakened following the military's biggest offensive in years last month. The army bombarded rebel camps from the air and sea and sent three battalions of soldiers to hunt militants down.

Oil firms have also increased security at offshore facilities, making a repeat of the Bonga attack harder.

Most of the oil infrastructure that MEND has targeted in recent weeks has been around Abiteye in Delta state, an area known to be hostile to the military and foreign oil companies.

Militants and local youths sabotaged oil pipelines in the area last November and again in March.

Although the area is supposed to have been secured by the military after last month's offensive, industry and security sources say it is virtually impossible to fully protect hundreds of kilometres of pipeline running through remote and largely unpopulated areas. (Editing by Nick Tattersall)