Berkshire, which once owned more than 11 per cent of the Chinese oil company''s publicly floated shares, said the decision followed criticism on PetroChina''s Sudan connection. The sale, however, was based on price, Buffett told Fox News in an interview. "It was 100 percent a decision based on valuation," he said.

The shares were worth $3.31 billion at the end of 2006, well above the $488 million that Berkshire paid for them, according to Berkshire''s latest annual report. Berkshire''s selling first surfaced in July. PetroChina shares have risen since then.

PetroChina, through its government-owned parent China National Petroleum Corp, is too closely linked to Sudan, its critics say. The White House blames the Sudanese government for what it calls genocide in the Darfur region.

Berkshire shareholders are expected to block the proposal to divest Berkshire''s PetroChina stake. Buffett too had opposed the proposal, though he said conditions in Darfur were deplorable and that he sympathized with people who wanted to change them.

But, he said, the selling would not improve conditions in Sudan, and that Berkshire should not divest automatically because it disagrees with a particular activity.