Soon the picture of Lyudmila Putin that adorns the most important desk in Moscow will give way to a similarly framed visage of Svetlana Medvedev.

After a controversial election, Vladimir Putin, who had run smack-dab into Russian term limits, will escort his hand-picked successor Dmitry Medvedev into the Russian presidency. Putin has lifted the country's economy while tamping down its drive toward democracy during his terms in office. But the diminutive former KGB official won't disappear: In a game of leapfrog that would bring smiles to faces in the Bush and Clinton clans, he's designated to become the prime minister in May when Medvedev is inaugurated.

Energy still in first place
But are opportunities to invest in his nation's companies likely to change 60 days or so from now? The answer, given the direction from which Medvedev has emerged, is, very little. If anything, oil and gas, the industry that's done much of the heavy lifting in boosting the Russian economy during the past decade, will continue to ascend in relative importance.

I make that claim for two reasons: First, as you probably know, Medvedev is the chairman of Gazprom, Russia's largest company and the world's leader in natural gas production and reserves. But beyond that, the share of oil, gas, and petroleum products in the value of Russia's total export base leaped from 38% in 1995 to 62% in 2006.

So if you're interested in hitching your financial wagon to Russian oil and gas, there's always swingin' Gazprom, an adjective I grab because of the company's employment of rock legends Deep Purple at its recent 15th birthday celebration in Moscow.

But seriously, I am still concerned about the power that's effectively ceded to Gazprom through its role as gas supplier to much of Europe. On Monday, for the second time in two years, the company cut off gas supplies to Ukraine (only partially this time), over a debt dispute.

And then there's Lukoil, the country's biggest oil company, which conducts its business in Iran, Columbia, and Venezuela, among other locations. Beyond that, it operates a string of former Getty and Mobil retail facilities in the U.S. And with the company's ADR having closed at $69.80 on Tuesday, its P/E ratio is less than 8.

And on to the mines
But if, like me, you're an aficionado of the mining and minerals group, Russia has opportunities for you there as well -- complete with the thrill-a-minute merger activity that characterizes the sector elsewhere. For instance, there's Norilsk Nickel, the world's biggest producer of nickel. The company appears to be in the early stages of a takeover war featuring as suitors Russian metals company Metalloinvest and giant aluminum producer United Co. Rusal.

Norilsk mines about one-fifth of the world's nickel. But as The Wall Street Journal noted on Tuesday, Rusal's avowed objective is to acquire the company, thereby taking a giant step toward building a mining behemoth that would rival the giants in other parts of the world.

And then there's Mechel (NYSE: MTL), a Moscow-based mining and metals company that produces coal, iron ore concentrate, and ferronickel. The company has recently expressed a desire to make a run at London-based Oriel Resources, which itself is largely involved in the production of chrome and nickel.

Can you hear me now?
But maybe you're a techie, or maybe you'd like to invest in businesses closer to the proletariat. If so, you might consider the nation's biggest wireless companies, Mobile Telesystems (NYSE: MBT) and the company with the desirable ticker, Vimpel-Communications (NYSE: VIP). Both companies are of similar size, and my slight preference goes to Mobile for its return on equity near 40% -- against just over 30% for Vimpel -- along with its tamer beta.

Conclusion
There are many other opportunities in Mother Russia. The key, however, is that the factors that have made the country's companies steadily more attractive are not apt to be reversed, no matter whose image sits atop the president's desk.

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Sadly, Fool contributor David Lee Smith must respond with a "nyet" when asked if he owns any of the companies mentioned above. Nevertheless, he welcomes your questions and comments. The Fool's disclosure policy has meaning in any language.