UPDATE 4-Nigerian youths blow up oil pipeline, output cut

(Updates with MEND comments, armed youths behind attack)

By Randy Fabi

ABUJA, June 21 (Reuters) - Armed youths blew up a Nigerian crude oil pipeline operated by U.S. major Chevron (CVX.N), a militant group said on Saturday, cutting more output from the world's eighth largest oil exporter.

The Movement for the Emancipation of the Niger Delta (MEND) said it was contacted by youths claiming responsibility for Thursday's attack on Chevron's Abiteye-Olero crude pipeline and commended their action.

The military said about 120,000 barrels per day of crude oil production were shut by the sabotage.

"For production to have stopped, this shows the damage was serious," said army Brigadier-General Wuyep Rintip, head of the government's Joint Task Force in the western Delta.

A Chevron spokeswoman confirmed that one of its pipelines was damaged, but declined to say how much output was affected.

A wave of attacks in the West African country has cut production by a fifth since early 2006, helping push world oil prices to record highs.

Thursday's incident came hours after a bold night-time militant attack on Royal Dutch Shell's (RDSa.L) main offshore oil facility that cut Nigeria's oil output by 10 percent.