liabilities high diversification needed, page-4

I see what you mean but BHP by themselves do not have the market power to individually control supply of iron ore. If BHP decide to cut back supply, Vale or Rio would step up to the plate to sell more.

Going into making steel to take out its biggest customers (i.e. Chinese steel mills) seems to be a very expensive let alone politically difficult way of meeting its objectives. And doesn't help with its conservative debt position either.

Working with Vale and Rio toward a more flexible iron pricing system seems to be the way to go and that is what they are doing now. A flexible system such as this ensures that iron ore is price at a market clearing price and removes this drama of annual price negotiations.