Posco (005490.SE) and other South Korean steelmakers are opposed to the proposed iron ore joint venture announced last week by miners Rio Tinto PLC (RTP) and BHP Billiton Ltd. (BHP), the Korea Iron & Steel Association said Wednesday.

"The joint venture may bring forth aggravated oligopoly in the iron ore market though the two miners say they will independently manage marketing and sales functions," the association said in a statement.

Posco Chief Executive Chung Joon-yang, at an annual steel industry event Tuesday, said the BHP-Rio joint venture wasn't positive for the steel industry.

His remarks followed a statement yesterday by the China Iron and Steel Association, which said it strongly opposed the joint venture.

"The joint venture agreement goes in the direction of a monopoly," the association said in a statement on its Web site.

-By Kyong-Ae Choi, Dow Jones Newswires; 822-2198-2236; kyong-ae.choi@dowjones.com