(Reuters) -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 $36 billion overall profit.

Rising interest rates and dividend payouts, as well as a rebound in performance at the Geico car insurer, have been helping Berkshire's insurance businesses generate more money, with profit up 38% from a year earlier.

That helped offset declines at other businesses including the BNSF railroad, where lower shipments of consumer goods and increased price competition from the trucking industry contributed to a 24% drop in overall profit.

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.

Operating profit rose 7% to $10.04 billion, or about $6,938 per Class A share, from $9.42 billion a year earlier.

Net income totaled $35.91 billion, or $24,775 per Class A share, compared with a year-earlier $43.62 billion loss.

Berkshire also said it had repurchased $1.4 billion of stock in the quarter.

It also remained a big net seller of stocks from its $353 billion equity portfolio - about half of which is Apple - shedding about $8 billion more stocks than it bought.

That helped push Berkshire's cash stake up to $147.4 billion as of June 30 from $130.6 billion three months earlier.

Net results included $25.9 billion of largely unrealized gains from investments and derivatives.

Those results are volatile because accounting rules require Berkshire to report unrealized gains even if it sells nothing. Buffett urges investors to ignore the fluctuations.

The quarter was the first to fully include results from truck stop operator Pilot, in which Berkshire now owns an 80% stake. Pilot contributed $114 million to operating profit.

Buffett turns 93 on August 30. He is worth $117.5 billion and the world's sixth-richest person, Forbes magazine said.

Berkshire Class A shares closed Friday at $533,600, about 2% below their record high. The shares are up 14% this year, while the Standard & Poor's 500 is up 17%.

(Reporting by Jonathan Stempel in New York; Editing by Angus MacSwan and Jan Harvey)