Description:The world's biggest miner, BHP Billiton has become more wary on the outlook for commodity markets, saying customers are starting to face tighter access to trade finance with some cutting production. BHP is the first miner to highlight that clients are starting to face tougher credit conditions. Speaking to shareholders in Australia, CEO Marius Kloppers was more cautious compared to the company's London AGM a month ago, when he only spoke of softer commodity prices.(1:18)