New Delhi, July 15 -- Warren Buffett said that the decision to build Berkshire Hathaway's massive stake in Alphabet was his own, and incoming CEO Greg Abel had no role in it. "I initiated it," Buffett told CNBC in the first public explanation of how Alphabet became one of Berkshire's biggest technology holdings.

"I am not doing anything that he doesn't approve of. He's not doing anything I don't approve of. We talk all the time, but he is the decider," the Berkshire chairman added, referring to his CEO successor Abel.

Berkshire Hathaway added nearly 40 million shares of Alphabet stock in the first quarter, spending an estimated $13 billion. In June, Abel negotiated another deal to buy 28.6 million shares through a $10 billion private pl...