Shares in South Korean steel maker POSCO dropped 5 percent on Monday, hit by worries that its strong earnings growth may slow later this year due to rising costs.

South Korea's POSCO said on Thursday it was weighing up a rise in steel prices and may bid for Daewoo Shipbuilding and Marine, which analysts say could fetch nearly 5 trillion won.

South Korean steel maker POSCO said on Friday it was inclined to raise steel prices after a surge of 65 percent in raw material iron ore prices.