Warren Buffett, the legendary investor and second richest man in the U.S., trimmed his company’s holding in PetroChina three times in the past two months. The sales of 138 million PetroChina shares brought a profit of $183 million, a 925% return.

Berkshire Hathaway, where Buffett is CEO, remains the second largest shareholder of PetroChina, after China National Petroleum Corporation (CNPC), a 100% Chinese government owned enterprise.

The billionaire bought the shares at 1.6 Hong Kong dollars per share in April 2003. The shares were sold in July, August and September for prices ranging from 11.47 to 12.4 Hong Kong dollars. Berkshire’s share in PetroChina dropped from 11.05% to 8.93% after the sales.

The simple profit taking, unexpectedly, has been lauded by human rights groups who cheer for Berkshire’s divesting from a Chinese company that has afflicted operations in Sudan, where millions of people were displaced and grave killings took place during the Darfur crisis.

There was enormous opposition since the company’s investment in PetroChina. In May, 809,995 A-share Berkshire holders and 8,471,129 B-share holders voted on a proposal to divest from PetroChina. Buffett, in a shareholder letter, listed three reasons to vote against the proposal.

First, it is PetroChina’s parent company, CNPC, who does business in Sudan – not PetroChina. In the same way that the U.S. government created Fannie Mae and Freddi Mac, CNPC may shape or control PetroChina’s operations, but PetroChina should in no way be responsible for what CNPC does.

Second, an investor should not divest because he or she disagrees with an investee’s certain activity. The letter pointed out that the shareholder who proposed to divest from PetroChina did not divest from Berkshire because she disagrees with its investment decisions.

Finally, even if CNPC stops its operation in China, there is no guarantee that the situation in Sudan will improve. That is because CNPC owns 40% of a Sudan venture whose primary assets are oil and fixed assets (oil refinery and transportation equipment). Therefore, the feasible divestment plan for CNPC would be to sell its 40% invest to the Sudanese government. The consequence would only make the Sudanese government financially stronger – but does that help the conflict?

The result: 97.5% shareholders voted against the proposal, and 1.8% voted for it.

The vote settled the issue – or Buffett may wish. Human rights groups continue calling Berkshire to divest from PetroChina. But many agree: the recent selling is just profit taking. Or who knows – maybe Buffett changed his mind on Darfur?