Berkshire Hathaway on Saturday posted its highest ever quarterly operating profit, while gains from stock holdings helped the conglomerate led by billionaire Warren Buffett swing to a nearly US$36 billion overall profit.

Rising interest rates, as well as a rebound in performance at the Geico car insurer, allowed Berkshire's insurance businesses to generate more money, with profit up 38 percent from a year earlier.

But those same rising interest rates have made it more costly to buy and renovate homes, hurting results at the Clayton Homes mobile home and building products businesses, and causing revenue at the RV unit Forest River to sink 34 percent.

The BNSF railroad, one of Berkshire's largest businesses, saw profit drop 24 percent, hurt by lower shipments of consumer goods, price competition from truckers, and higher pay for employees.

Investors closely watch Berkshire because of Buffett's reputation, and because results from the Omaha, Nebraska-based company's dozens of operating units often mirror broader economic trends.

Those units also include Berkshire's namesake energy company, several industrial companies, and familiar brands such as Dairy Queen, Duracell, Fruit of the Loom and See's Candies.

Quarterly operating profit topped US$10 billion for the first time but grew just 7 percent, in part from recent purchases of the Alleghany insurer and Pilot truck stop operator. (Reuters)