Berkshire Hathaway’s insurance arm made $US440 million ($637.8 million) in net underwriting profit in the third quarter, which was marginally weaker than the $US441 million ($639.2 million) achieved a year earlier.

Overall net earnings in the nine months to September declined to $US1.18 billion ($1.71 billion) from $US1.79 billion ($2.6 billion).

Third-quarter insurance investment income rose to $US1.48 billion ($2.1 billion) from $US1.24 billion ($1.8 billion), taking the year-to-date total to $US4.09 billion ($5.9 billion).

Motor insurer Geico fared the worst among the three Berkshire-owned insurance units. The business recorded a sharp fall in pre-tax underwriting earnings to $US376 million ($545 million) from $US627 million ($908.9 million) as losses and loss adjustment expenses rose 9.2% to $US7.3 billion ($10.6 billion).

Berkshire Hathaway Reinsurance Group returned to the black with a pre-tax profit of $US52 million ($75.4 million), erasing the $US163 million ($236 million) it lost a year earlier.

Commercial insurance provider Berkshire Hathaway Primary Group improved its results to $US153 million ($221.8 million) from $US135 million ($195.7 million).

Berkshire’s group-wide net income in the third quarter fell to $US16.5 billion ($23.9 billion) from $US18.5 billion ($26.8 billion).