UPDATE 1-Marubeni sells Aussie power plant stake to S.Korea buyer -source

* Company spokeswoman confirms sale, but not details

* 850 MW plant is located in southern Queensland

(Adds comment from Marubeni)

TOKYO, Jan 7 (Reuters) - Japanese trading house Marubeni Corp has sold its 30 percent stake in Australia's Millmerran Power Station to a South Korean buyer for less than A$200 million ($179 million), a source with direct knowledge of the deal said on Tuesday.

A company spokeswoman confirmed the sale of the stake in the 850-megawatt coal-fired thermal power plant located in southern Queensland, but declined to comment on the value or the buyer.

"It was a straight forward transaction," the source said, speaking on condition of anonymity, adding that since the plant sells power wholesale, its profits can be very volatile.

The plant, which also has a coal mine connected to it, came online in 2003 and supplies electricity to about 1.1 million homes, according to the facility's website. ($1 = 1.1159 Australian dollars)

(Reporting by James Topham; Editing by Chris Gallagher and Joseph Radford)

((james.topham@thomsonreuters.com)(+813 6441 1858)(Reuters Messaging: james.topham.thomsonreuters.com@reuters.net))

Keywords: MARUBENI AUSTRALIA/POWER