• Berkshire Hathaway tripled its Alphabet stake and placed a new bet on Delta Air Lines last quarter.
• The company appears to have sold all of the departed Todd Combs' stock picks.
• Warren Buffett's successor as CEO, Greg Abel, exited bets including Amazon, Visa, and Mastercard.

Warren Buffett's successor certainly isn't shy about shaking things up.

Greg Abel, who took over as Berkshire Hathaway's CEO on January 1, made sweeping changes to the conglomerate's holdings in the first three months of this year, a regulatory filing revealed on Friday.

Berkshire built a fresh stake in Delta Air Lines worth $2.6 billion at the end of March, marking its return to owning airline stocks.

The company also more than tripled its stake in Google-parent Alphabet, a key player in the AI boom.

After purchasing nearly 18 million shares of the search-and-advertising giant in the third quarter of last year, it didn't touch the position in Buffett's final quarter as CEO.

But that changed last quarter, as it ramped up its investment to almost 58 million shares, worth around $17 billion at the end of March.

Abel appeared to offload all of the stocks picked by Todd Combs, previously one of Buffett's two investment managers. Buffett, who remains Berkshire's chairman, announced in December that Combs had resigned to join Jamie Dimon at JPMorgan.

Berkshire exited its positions in Visa, Mastercard, UnitedHealth, Domino's Pizza, Amazon, Charter, Diageo, and several other companies. The disposals reduced its total number of holdings to around two dozen.

Abel also pared other holdings including Chevron, Nucor, and Constellation Brands.

On the other hand, Abel and his team added Macy's to their portfolio, and roughly tripled the size of the New York Times stake they established in the preceding quarter, boosting it to around 15 million shares valued at around $1.3 billion on March 31.

Berkshire foreshadowed significant changes to its stock portfolio in its first-quarter earnings earlier this month. The report showed that it sold about $24 billion worth of stocks, and bought around $16 billion worth.

The Delta wager is likely to surprise close followers of Berkshire.

Buffett famously sold his stakes in the "big four" US airlines in April 2020, admitting he'd made a "mistake" by betting on them. In his shareholder letter for 2007, he described the airline business as a "bottomless pit" and quipped:

"Indeed, if a farsighted capitalist had been present at Kitty Hawk, he would have done his successors a huge favor by shooting Orville down."