Oct. 10 (Bloomberg) -- Billionaire Warren Buffett's Berkshire Hathaway Inc. cut its stake in PetroChina to 3.1 percent of the publicly held shares as of Sept. 30, from 5.44 percent five days earlier.

The company held 652.9 million of Beijing-based PetroChina's Hong Kong-traded shares, and none of its American depositary receipts as of Sept. 30, according to a U.S. regulatory filing today by the Omaha, Nebraska-based company. Berkshire has been cutting its stake over the past three months in China's largest oil producer, majority owned by the Chinese government.

Human rights groups have been calling on Buffett to sell his PetroChina shares. The company's Chinese parent is the largest foreign developer of oil fields in Sudan, accused by the U.S. of supporting genocide in the African nation's western Darfur region. Buffett rejected as ineffectual a Berkshire shareholder's proposal calling for divestment, and it was voted down 53-to-1 at the annual meeting in May.

``Is he actually for one of the few times in his life acknowledging public sentiment about one of his holdings?'' said Frank Betz, who helps manage $800 million at Carret Zane Capital Management, including Berkshire shares. ``He's under public pressure because some people don't like him being in the company, and he's already done well.''

Berkshire spokeswoman Jackie Wilson declined to comment.

Biggest Shareholders

PetroChina rose 2.1 percent to HK$14.58 in Hong Kong on Wednesday. The stock has gained 32 percent this year and reached a record HK$14.94 on Oct. 2. Berkshire bought its stake for less than HK$1.70 a share in April 2003, paying $488 million for the holding.

As of the end of last year, Berkshire was the largest non- government shareholder, with about 13 percent of the publicly held stock, worth $3.3 billion, according to Berkshire's annual report. As of June 30, Berkshire held ADRs worth the equivalent of 65.9 million Hong Kong shares, according to a regulatory filing.

The two largest PetroChina shareholders are now mutual fund manager Franklin Resources Inc., based in San Mateo, California, with 1.1 billion shares, and New York-based JPMorgan Chase & Co., the third-largest U.S. bank by assets, according to Bloomberg data.

On Sept. 25, Berkshire sold 220.5 million shares, cutting its stake to 5.44 percent, according to a Hong Kong stock exchange filing yesterday.

Ethics and Profit

The Save Darfur Coalition on Sept. 5 urged investors including Fidelity Investments, Vanguard Group and American Funds to sell their PetroChina stakes.

``We don't know if it's an investment decision or a political decision,'' said Betz, whose firm is based in Warren, New Jersey. ``When you've got that kind of profit, you can't get in much trouble taking your money and running.''

Buffett, 77, transformed a failing textile maker over four decades into a $193 billion investment and holding company with businesses ranging from ice cream to insurance and corporate jet leasing.

The world's third-richest man according to Forbes magazine, Buffett often scolds corporate America for putting profits ahead of ethics. Last year he pledged the bulk of his fortune to the Bill and Melinda Gates Foundation, a gift valued at the time at about $37 billion.

To contact the reporter on this story: Josh P. Hamilton in New York at jphamilton@bloomberg.net

Last Updated: October 10, 2007 19:53 EDT