A major hurdle cleared and a solid opportunity for Foolish investors, Anglo-Australian mining giant Rio Tinto (NYSE:RTP) last week gained permission from the Canadian government to purchase Canada's big aluminum company, Alcan (NYSE:AL).

Of course, the companies are not yet home-free in fulfilling their announced nuptials. The $38.1 billion deal still must be blessed by regulatory authorities in France, Britain, and Australia. It must also stand for a vote of Rio Tinto shareholders to be held next week in London and two weeks later in Australia. The deal is expected to be consummated during the fourth quarter.

The combined company, which will be called Rio Tinto Alcan, will be the world's top producer of aluminum and bauxite. In fact, its largest rival will be Pittsburgh-based Alcoa (NYSE:AA), which effectively chased Alcan into Rio Tinto's arms last spring by launching a hostile offer for its Canadian rival. And with the metals and mining sector being awash with combinations of late, those events followed copper producer Freeport McMoRan's (NYSE:FCX) March purchase of its larger rival Phelps Dodge. It will also likely be sandwiched between a pair of acquisitions by U.S. Steel (NYSE:X).

At the same time, the acquisition has emphasized the tremendous value that appears to exist in Rio Tinto. With our topsy-turvy market inducing a flight to quality among investors, and with the international economy seeming stronger than that of the U.S., Rio Tinto appears to be a name with which Fools should familiarize themselves.

In addition to aluminum, the $24 billion company produces copper, diamonds, energy, coal, uranium, gold, industrial minerals, and iron ore. It operates across much of the world, including North America, Europe, Asia, Australia, and New Zealand.

But beyond its scope, I find a lot to like in its metrics. For instance, many Fools know that I'm intrigued by the PEG ratio as a reflection of whether or not the market has factored in a company's likely expansion. Rio Tinto's is an unusually attractive 0.5. Now, mix that together with a 38.2% return on equity, an 11.4 times forward P/E (December 2008), and a balance sheet that's so strong the company was easily able to borrow the funds necessary for the Alcan deal. Next, sprinkle on an indicated forward annual dividend yield of 1.5% -- its five-year average rate has been 2.7% -- and you have the recipe for a company that could fortify your investment portfolio nicely.

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