Chinalco holds a 9.3 percent stake in Rio, and the large deal planned last year envisioned expanding that to 18.5 percent. But the transaction collapsed amid Australian concerns about China's growing influence over Australia's mineral wealth. Australian-Chinese relations soured further after the four Rio Tinto employees were arrested in Shanghai in July. They were later charged with accepting bribes and stealing trade secrets. The trial of the four employees is to begin on Monday, almost nine months after they were detained. Kevin Rudd, the prime minister of Australia, warned this week that the "world will be watching" the proceedings. The Chinese authorities have said the portion of the trial dealing with bribery claims will be open, but the part concerning charges of infringement of commercial secrets will be closed, even to Australian diplomats.