The second quarter will likely be the most difficult period this year for Posco (PKX), the world's fourth-largest steelmaker by output, the company's chief executive said Tuesday.

Chung Joon Yang also said that steelmakers will not welcome a planned iron ore joint venture announced Friday by Rio Tinto PLC (RTP) and BHP Billiton Ltd. (BHP). He was speaking at an annual steel industry event.

He also said that the company continues to be in talks with BHP and Brazil's Vale S.A. (VALE) on iron ore prices. Chung added that he expects to conclude talks with BHP at price levels similar to those reached with Rio Tinto.

Rio Tinto recently finalized a deal with Posco to cut 2009-10 iron prices by 33% to 44%.

Chung added that Posco has no plans to acquire companies involved in raw materials for the industry for now.

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