Vertical integration is back in vogue in steel, as the industry tries to break the stranglehold of iron-ore and coal suppliers. ArcelorMittal (MT), the world's No. 1 steelmaker, plans to triple output at its iron-ore mine in Brazil by 2014. South Korea's Posco (PKS), meanwhile, has earmarked $5 billion for investment in overseas mines. The race to find other sources of key materials has taken on new urgency as iron-ore producers have exploited their market power to dramatically raise prices.