Berkshire also eliminated its small stakes in Organon & Co, a Merck spinoff specializing in contraception and other women's health products, and telecommunications company Liberty Global Plc.
It disclosed new investments of $475 million in Royalty Pharma Plc, which buys drug royalties, and $99 million in flooring retailer Floor & Decor Holdings Inc.
The changes were disclosed in a regulatory filing detailing Berkshire's U.S.-listed holdings as of Sept. 30.
Shares of Royalty Pharma rose more than 5% after the market close, a common occurrence after Berkshire reveals new stakes. Royalty Pharma did not immediately respond to requests for comment.
Investors monitor Berkshire's investments closely to see where Buffett and his investment managers Todd Combs and Ted Weschler see value. The filings do not say who bought and sold what, though Buffett generally handles larger investments.
While Berkshire ended September with $310.7 billion of equity holdings, it sold $2 billion more stocks than it bought in the third quarter, and has been a net seller for all of 2021.
About 41% of Berkshire's stock investments are in Apple, with another 29% in Bank of America Corp, American Express Co and Coca-Cola Co.
The sales and Buffett's nearly six-year drought in buying large whole companies have contributed to Berkshire's boosting its cash holdings to a record https://www.reuters.com/article/berkshire-results-idCAKBN2HR092 $149.2 billion, despite at least $21.9 billion of stock buybacks this year.
They have also disappointed investors who have seen Berkshire's stock price significantly lag the Standard & Poor's 500 since the end of 2018.
Berkshire's respective share stakes in AbbVie and Bristol-Myers fell 30% and 16% in the quarter.
Royalty Pharma helps fund late-stage clinical trials and product launches in exchange for future royalty streams, and sometimes buys royalties from drug developers.
Its larger revenue streams come from Vertex Pharmaceuticals Inc treatments for cystic fibrosis, Biogen Inc's Tysabri for multiple sclerosis, and AbbVie's Imbruvica for various cancers.
The company's share price has recently traded about 50% above its initial public offering price in June 2020, but below where it closed on its first trading day.
Berkshire is based in Omaha, Nebraska. It also owns dozens of businesses including the BNSF railroad, Geico auto insurance and Dairy Queen ice cream.
(Reporting by Jonathan Stempel in New York;Editing by Chris Reese and Stephen Coates)
By Jonathan Stempel