Billionaire investors Warren Buffett and Carl Icahn may differ in investment strategies but they both own sizable stakes in Tyco International Ltd., an analysis of recent investment documents shows.

From the end of 2005 to March 31, 2006, Icahn nearly doubled his stake in Tyco to 3.95 million shares from 2 million shares, according to documents filed with the U.S. Securities and Exchange Commission this week.

Meanwhile, Buffett, through his Berkshire Hathaway Inc. investment and insurance firm, left a 10 million share investment in Tyco unchanged.

A month ago, Bermuda-based Tyco agreed to pay $50 million to settle accounting fraud charges with the SEC, without admitting or denying any wrongdoing.

The government accused Tyco of overstating its results between 1996 and 2002 in an accounting scandal that was overshadowed by details about its former chief executive, Dennis Kozlowski, who was later convicted of looting the conglomerate. His lavish spending on such things as a $2 million birthday party and a $6,000 shower curtain came to symbolize corporate excess.

Shares of Tyco are also being held by the chairman of Microsoft Corp. and his wife through their Bill & Melinda Gates Foundation, according to quarterly investment documents filed with the SEC this week. The foundation seeks to improve health and alleviate poverty in the developing world.

The Gates foundation left its investment of 4.5 million Tyco shares unchanged from the end of 2005 to the end of March 2006, the documents showed.

An analysis of quarterly documents filed with the SEC also showed that Berkshire and the Gates foundation separately hold investments in warehouse club Costco Wholesale Corp. The foundation owned 4.5 million shares while Berkshire held 5.3 million shares.

The Gates foundation and Berkshire also hold shares of Home Depot Inc., the world's largest home improvement retailer.

Berkshire dropped its investment to about 4.2 million shares on March 31, from 5 million shares at the end of 2005. The Gates foundation left its 935,000 shares unchanged during the quarter.

Another prominent investor, George Soros, sold shares in some companies that Berkshire also holds.

The Soros Fund Management LLC sold 4 million shares of financial services company American Express Co., 45,500 shares of brewer Anheuser-Busch Cos. Inc., 11,017 shares of payment services group First Data Corp. and 2,868 shares of newspaper and magazine publisher Washington Post Co.

Buffett, according to recent documents, left unchanged the millions of shares he holds in those same companies which are a small part of his overall portfolio.

Soros also increased his stake in credit rating agency Moody's Corp. to 86,300 shares in the first quarter, from 40,200 shares at the end of 2005. Berkshire did not change its holdings in Moody's, which stood at 48 million shares.