The numerous companies of Warren Buffett's Berkshire Hathaway Inc. have been running completely independently for decades. That is not always the case anymore.
Top executives from Berkshire units are now regularly gathered to share strategies and best practices. Some of these companies participate in buying cohorts to take advantage of group prices for goods such as travel and commodities. Last year, employees from more than 40 Berkshire companies met at the company's headquarters, Omaha, Neb., To discuss sustainability.