In 1973, Berkshire began to acquire stock in the Washington Post Company. Buffett became close friends with Katharine Graham, who controlled the company and its flagship newspaper and joined its board. In 1974, the SEC opened a formal investigation into Buffett and Berkshire's acquisition of Wesco Financial, due to possible conflict of interest. No charges were brought. In 1977, Berkshire indirectly purchased the Buffalo Evening News for $32.5 million. Antitrust charges started, instigated by its rival, the Buffalo Courier-Express. Both papers lost money until the Courier-Express folded in 1982.

In 1979, Berkshire began to acquire stock in ABC. Capital Cities announced a $3.5 billion purchase of ABC on March 18, 1985, surprising the media industry, as ABC was four times bigger than Capital Cities at the time. Buffett helped finance the deal in return for a 25% stake in the combined company.[42] The newly merged company, known as Capital Cities/ABC (or CapCities/ABC), was forced to sell some stations due to Federal Communications Commission ownership rules. The two companies also owned several radio stations in the same markets.[43]

In 1987, Berkshire Hathaway purchased a 12% stake in Salomon Inc., making it the largest shareholder and Buffett a director. In 1990, a scandal involving John Gutfreund (former CEO of Salomon Brothers) surfaced. A rogue trader, Paul Mozer, was submitting bids in excess of what was allowed by Treasury rules. When this was brought to Gutfreund's attention, he did not immediately suspend the rogue trader. Gutfreund left the company in August 1991.[44] Buffett became chairman of Salomon until the crisis passed.[45]

In 1988, Buffett began buying The Coca-Cola Company stock, eventually purchasing up to 7% of the company for $1.02 billion.[46] It would turn out to be one of Berkshire's most lucrative investments and one which it still holds.