The Globe and Mail reports in its Saturday edition that Glencore PLC will play a crucial role in determining whether the Teck-Anglo American deal goes ahead and, if so, under which terms. The Globe's Eric Reguly writes that in the global mining industry, Glencore is a famously merciless negotiator and will no doubt employ its leverage to the hilt. Anglo and Teck, beware. Driving the creation of Anglo Teck, as the enlarged company is to be called, are two enormous copper mines high in the Andes of northern Chile, Quebrada Blanca (QB) and Collahuasi. They are only 11 kilometres apart, and putting the two together in the name of "synergies" (cost-cutting) is driving the proposed marriage. Operating QB and Collahuasi as one makes perfect strategic sense, but the complex ownership structure of the mines means a full-fledged merger make this difficult. QB is 60 per cent owned by Teck, 30 per cent by Japan's Sumitomo and 10 per cent by Coldeco, Chile's state-owned mining company. The much larger Collahuasi is 44 per cent owned by Anglo, 44 per cent by Glencore and 12 per cent by Japan's Mitsui. In other words, Anglo and Teck will have to make nice with four other shareholders of the mines to get their deal done.