Republicans in the U.S. Congress, who have criticized Warren Buffett's approach to tax policy, are largely holding onto their investments in the billionaire's Berkshire Hathaway Inc., personal financial-disclosure forms show.

Berkshire investors in Congress include Senator Orrin Hatch, the top Republican on the Finance Committee; Representative Dave Camp, the chairman of the House Ways and Means Committee; and Representative Paul Ryan, chairman of the House Budget Committee. Financial disclosure forms filed by members of Congress, released Thursday, require lawmakers to state the value of holdings in broad ranges.

"I haven't changed any of my investments since I've been in the Senate and haven't purchased any stocks since I've been in the Senate," said John Barrasso of Wyoming, who is the fourth-ranking Republican in the Senate and owns between $100,000 and $250,000 of Berkshire stock.

Buffett, the 81-year-old billionaire chairman and chief executive officer of Berkshire, has called for higher taxes for the highest U.S. earners, including himself. President Barack Obama, a Democrat, began campaigning in September 2011 on the so-called "Buffett rule" that would require a minimum tax rate of 30 percent for people with incomes exceeding $2 million.

In April, the Senate voted 51-45 to advance legislation implementing the rule. That fell short of the 60 votes needed for the measure to move forward.

Camp, Hatch

Camp and Hatch are the top two Republicans on tax policy in Congress. Camp, a Michigan Republican, bought Berkshire corporate bonds worth between $15,000 and $50,000 in December 2011 and holds up to $100,000. Hatch, of Utah, has between $30,000 and $100,000 in Berkshire stock, including at least $16,000 purchased in October 2011.

"The congressman's financial information has been fully disclosed in full compliance with the law and rules of the House," said Sage Eastman, a spokesman for Camp. The congressman called the Buffett rule a "job-killing tax hike" in April.

Antonia Ferrier, a spokeswoman for Hatch, said the senator doesn't manage his stocks. Hatch has criticized the Buffett rule, calling it part of Obama's "political games."

Political Views

At Berkshire's annual meeting last month, Buffett took questions along with Vice Chairman Charles Munger. Buffett was asked if he should mute his political views, prompting applause from some in the crowd at Omaha's CenturyLink Center.

"When Charlie and I took this job, we did not decide to put our citizenship in a blind trust," Buffett said.

Buffett didn't immediately respond to a request for comment sent to an assistant today.

Berkshire's Class A shares slumped 4.7 percent to $114,755 last year, while the Standard & Poor's 500 Index was unchanged. Buffett has surpassed the performance of the stock benchmark during the past four decades, increasing Berkshire's book value per share more than 5,000-fold since 1964.

Other Republicans, including Senator Jon Kyl of Arizona, Representative Ed Whitfield of Kentucky and Representative Dan Benishek of Michigan, sold their Berkshire holdings during 2011.

Kyl, the second-ranking Republican in the Senate, said the stock was in a mutual fund he doesn't control.

'Never Looked'

"I've never known what they are," he said. "I've never looked. So I can't answer any questions."

At least two lawmakers have more than $1 million invested with Buffett. Senator Ben Nelson, a Democrat who represents Buffett's home state of Nebraska, owns more than $1.5 million in Berkshire stock, including at least $60,000 bought in 2011.

Representative Tom Petri, a Wisconsin Republican, has between $1 million and $5 million in Berkshire stock. Senator Claire McCaskill, a Missouri Democrat, has at least $515,000 in stock.

Other lawmakers with Berkshire holdings include Representative Steve Cohen, a Tennessee Democrat, Representative Ander Crenshaw, a Florida Republican, Senator Tom Udall, a New Mexico Democrat, and Senator Tom Coburn, an Oklahoma Republican.

The forms cover lawmakers' holdings as of the end of 2011 and their transactions during that year.

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