Warren Buffett is considered one of the world's greatest investors
Billionaire Warren Buffett's investment firm has reported that profits almost tripled in the third quarter.
Berkshire Hathaway said its net profit was $3.2bn (£1.9bn) in the three months to September, compared to $1.1bn in the same period last year.
But most of that was due to an unrealised $1.1bn gain on some derivatives its insurance unit holds.
Mr Buffett last week said he was taking control of a US railroad in his biggest deal to date.
Berkshire agreed to buy the stock that it does not already own in Burlington Northern Santa Fe (BNSF), the biggest US haulier of products such as corn and coal, for about $26bn in cash and stock.
Mr Buffett, the world's richest man last year, said that the deal was "an all-in wager on the economic future of the United States".
The third-quarter results do not include that deal.
Excluding the derivative and investment gains, Berkshire's operating profit in the third quarter was flat at $2.06bn.
The company's revenue was $29.9bn, up from $27.9bn a year ago.
Berkshire has major investments in such companies as beverage giant Coca-Cola and US bank Goldman Sachs.