Put some coffee on the boil. Australian mining and energy giant BHP Billiton (NYSE:BHP) may just be awakening.

It's already been discussed as a likely participant in both Freeport-McMoRan's (NYSE:FCX) recent acquisition of Phelps Dodge and Alcoa's (NYSE:AA) still-fresh offer for its Canadian rival Alcan (NYSE:AL). Now rumors are swirling that BHP Billiton may have its eye on another, only slightly smaller mining concern, London-based Rio Tinto (NYSE:RTP). Combining these two behemoths would create a company with revenue approaching $60 billion and interests in (brace yourself) petroleum, aluminum, base metals, carbon steel materials, energy coal, stainless steel materials, uranium, gold, and industrial materials.

Any deal uniting the two might reach or exceed a whopping $100 billion. And from a geographic perspective, the operations of the combined company would virtually ring the world. In addition to its Australian homeland, Billiton is heavily involved in South America, Africa, and Canada. For its part, Rio Tinto operates largely in North America, Europe, Asia, Australia, and New Zealand.

Propelled by a worldwide rise in commodities prices, the mining industry seems poised to become a hotbed of merger activity. Last autumn, when New Orleans-based copper producer Freeport first wooed its far larger Phoenix-based copper and molybdenum rival, Phelps Dodge, the market assumed that Freeport would likely get crowded out by bids from BHP Billiton or perhaps Southern Copper (NYSE:PCU). And earlier this week, when Alcoa disclosed its offer for Alcan, many observers immediately suggested both Billiton and Rio Tinto as possible interlopers.

Amid speculation of yet another mining megadeal, Rio Tinto's shares had risen roughly 15% at midday on Wednesday. These are two very strong companies with attractive valuations, and since either would permit Fools to participate in the expansion of many overseas economies, I'd call any careful study and analysis of both Billiton and Rio Tinto time well spent.

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Fool contributor David Lee Smith does not own shares in any of the companies mentioned. He welcomes your questions or comments. The Motley Fool has a disclosure policy.

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