Even Perry Mason couldn't have executed a surprising courthouse double-flip like this one. On Monday, with the world watching, four Rio Tinto (NYSE: RTP) employees became bribery defendants in a court in China.

The four, who were detained in July, include one Chinese-born Australian national, Stern Hu, and three Chinese citizens. The foursome represented Rio Tinto's interests in the sale of iron ore -- a key ingredient in the manufacture of steel -- to Chinese steelmakers. They were first charged with stealing China's state secrets, but those charges were later reduced to stealing commercial secrets and taking bribes. But rather than staunchly declaring their innocence as the trial began, they shocked the world by all pleading guilty.

It was generally thought to be less than coincidental that their arrests occurred soon after their company had rejected a bid by Aluminum Corp. of China (NYSE: ACH) -- or Chinalco -- to invest $19.5 billion in a doubling of its current 9% interest in Rio. Instead, Rio Tinto used a rights offering and a joint venture with Australia's mining behemoth BHP Billiton (NYSE: BHP) to raise funds to repay debt it incurred when it beat out Alcoa (NYSE: AA) for the 2007 acquisition of Alcan.

Also in the major-coincidence department, the very day the employees' trial began, Rio CEO Tom Albanese was scheduled to speak at a development conference in Beijing along with Ford (NYSE: F) CEO Alan Mulally and Chinese Premier Wen Jiabao. Clearly, Albanese's topic, "Strengthening Global Cooperation for a Mutually Beneficial Future," contained at least a touch of irony. He apparently referred only in passing to the trial during his comments.

But lest you think that Rio Tinto and China are at swords' points and will likely remain so, on Friday the two announced a joint venture for the Simandou iron-ore project in Guinea. Rio currently owns 95% of the project, but for $1.35 billion will sell 47% of its stake -- or 44.65% of the total -- to Chinalco. The remaining 5% is owned by International Finance Corp. (NYSE: IFK), with the government of Guinea holding an option to buy 20% of the project. This deal convinced me that, events at the trial notwithstanding, relations between China and Australia will only strengthen as time passes.

As you probably know, Rio, Vale (NYSE: VALE), and BHP control global reserves of many metals and minerals. That status clearly won't change, nor, likely, will my feeling that the three companies all deserve close attention from Foolish investors.  

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