Berkshire Hathaway ( NYSE: BRK.A ) ( NYSE: BRK.B) on Saturday posted a nearly 4% decline in quarterly operating profit, hurt by soft insurance underwriting earnings and a $3.8B hit to its stake in ketchup giant Kraft Heinz ( KHC ).

(Reuters) -Warren Buffett's Berkshire Hathaway on Saturday wrote down part of its investment in Kraft Heinz, and reported a 4% decline in second-quarter operating profit as premiums from insurance underwriting fell.

Berkshire said the 12 per cent quarterly decline in insurance underwriting profit stemmed primarily from reinsurance businesses and some smaller insurance businesses. Geico, its best-known insurance business, saw pre-tax underwriting profit rise 2 per cent, as a 5 per cent increase in premiums offset a smaller rise in accident losses.