* Q3 Class A shr $2,087 vs $682 a year ago

* Operating profit down less than 1 percent

* Results follow announced Burlington Northern takeover (Adds comments, financial details and background throughout)

By Jonathan Stempel and Lilla Zuill

NEW YORK, Nov 6 (Reuters) - Warren Buffett's Berkshire Hathaway Inc (BRKa.N: Quote, Profile, Research) (BRKb.N: Quote, Profile, Research) on Friday said quarterly earnings tripled, as rising stock markets boosted its investment holdings and a quiet hurricane season contributed to higher insurance profit.

Results were announced three days after Buffett revealed the biggest acquisition in his 44 years running Berkshire, a $26 billion takeover of Burlington Northern Santa Fe Corp (BNI.N: Quote, Profile, Research). Berkshire had already owned 23 percent of the nation's second-largest railroad operator.

Third-quarter net income for Omaha, Nebraska-based Berkshire rose to $3.24 billion, or $2,087 per Class A share, from $1.06 billion, or $682, a year earlier.

Excluding investments, operating profit fell less than 1 percent to $2.06 billion, or $1,325 per share, from $2.07 billion, or $1,335. On that basis, analysts expected profit of $1,308.25 per share, according to Thomson Reuters I/B/E/S.

Revenue rose 7 percent to $29.9 billion, though Berkshire said the effects of a global recession hurt results for several manufacturing, apparel and retailing units, as some customers "dramatically" reduced spending.