RAPAPORT... Revenue from the retail division of Warren Buffett's Berkshire Hathaway fell 2.3% year on year in the second quarter amid supply-chain disruptions.The segment - which includes jewelry chains Borsheims, Helzberg Diamonds and Ben Bridge Jeweler - saw sales decrease to $4.88 billion, the company reported Saturday. The drop was caused primarily by the segment's automobile category, which represents 65% of total revenue for the division. Car sales declined because of a global chip shortage and supply challenges.Pretax earnings for the entire retail unit slipped 3.5% to $443 million in the three months ending June 30. Revenues from manufacturing of consumer products, which includes jewelry maker Richline Group, climbed 14% to $4.35 billion, while pretax earnings fell 10% to $451 million.Image: A Borsheims store in Nebraska. (Borsheims)