Warren Buffett speaks during the Berkshire Hathaway Annual Shareholders Meeting in Omaha, Nebraska, on May 3, 2025.Warren Buffett's Berkshire Hathaway is closing in on a deal to buy Occidental Petroleum's petrochemical unit OxyChem for roughly $10 billion, the Wall Street Journal reported Tuesday. The potential deal, which could finalize within days per the Journal, could be Berkshire's largest since 2022 when it bought insurer Alleghany for$11.6 billion. That deal was announced in March of that year and c ...