The company headed by investment guru Warren Buffett is defending its investment in a Chinese business that has been accused of backing the Sudanese government.

Questions from the media, shareholders and others about PetroChina Co. prompted Buffett's company, Berkshire Hathaway, to post a notice on its website on Friday.

Sudanese protesters reject foreign involvement in Darfur during a demonstration in Khartoum in 2006.
(Abdel Raouf/Associated Press)

It said that PetroChina does not do business in Sudan. It also argued that compelling companies to sell investments in Sudan would help the Sudanese government because it would end up owning the assets.

Activists say that oil companies working in Sudan are paying the government taxes, and the government is responsible for the disaster in Darfur, where hundred of thousands have died.

The activists have been pressuring U.S. investors, especially university pension funds, to not do business with companies with interests in Sudan.

The unsigned statement on Berkshire's website said it agrees that "conditions in Sudan are deplorable and sympathizes with people who want to remedy them."

But it rejects the contention that PetroChina is working in Sudan.

"We have seen no records, including the various materials we have received from pro-divestment groups, that indicate PetroChina has operations in Sudan."

Berkshire said PetroChina's parent company does, but a subsidiary cannot be held responsible for what the parent does.

Canada's Talisman Energy caused controversy for years because of its Sudan involvement, but sold the investment in 2003.

Berkshire owns about 2.3 billion shares (1.3 per cent of the total) in PetroChina. The company's web statement is unusual because it has a policy of not commenting on its investments.

PetroChina's website said it's China's largest petroleum producer. "Currently, all of the company's petroleum and natural gas reserves and production-related assets are located in China."

With files from the Associated Press