UPDATE 1-Macarthur Coal confirms POSCO's 10 pct stake

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PERTH, July 1 (Reuters) - Australia's Macarthur Coal Ltd (MCC.AX) confirmed on Tuesday that South Korea's POSCO (005490.KS) had bought a 10 percent stake in the company from founder Ken Talbot.

Macarthur earlier requested a trading halt as it sought to confirm media reports which said Posco had bought shares from Talbot at a price of A$20 a share.

"We have a long-term relationship with Posco as a customer and we are pleased they have expanded the relationship to become a substantial shareholder of Macarthur Coal," Macarthur Chairman Keith De Lacy said in a statement. Posco said on Monday it would buy a 10 percent stake of Macarthur for $404 million, becoming the third overseas investor to hold a major stake in the Australian miner, in a move that could block any takeover of the company [ID:nSEO281490].

The sale came just a week after top shareholder Talbot quit the board to give himself more flexibility to deal with his remaining stake, which stood at 19.76 percent at the time.

The world's largest steelmaker, ArcelorMittal, also said on Monday it had acquired another 5 percent of Macarthur from Talbot and raised its stake in the coal miner to 19.9 percent.

ArcelorMittal is now Macarthur's largest shareholder, with Chinese group CITIC close behind with a 17.7 percent interest.

Under Australian law, a takeover bid must be launched if any one party acquires more than a 20 percent stake in a company.

Shares in Macarthur, which supplies steel mills with more than a third of the world's pulverised coal, ended Monday trade at A$16.87. They will resume on Wednesday.

The company's shares struck an all-time high of A$21.19 last month and have gained about 71 percent since the start of the year. (Reporting by Fayen Wong; Editing by James Thornhill)