Warren Buffett's Berkshire Hathaway Boosts Charter Stake, Hints At New Purchase

Warren Buffett's Berkshire Hathaway Inc. said Friday it boosted its stake in cable-television operator Charter Communications Inc., and signaled it may have another large investment planned after agreeing to buy Precision Castparts Corp. in its largest-ever purchase. Berkshire also appeared to have shed its stakes in oilfield-equipment provider National Oilwell Varco Inc. and refiner Phillips 66 in the second quarter, as the oil industry struggles with falling prices.