Investing.com -- Broadcom shares gained over 6% in premarket trading Tuesday after Alphabet unveiled plans to raise $80 billion in equity, a massive fundraise aimed at accelerating its AI infrastructure buildout.

Broadcom has a long-term deal with Google to develop and supply custom AI chips and other components for the company’s next-generation AI racks through 2031. It also struck an agreement with Anthropic to provide the AI startup access to roughly 3.5 gigawatts of AI computing capacity drawing on Google’s processors, starting in 2027.

The fundraising package includes a $10 billion private placement to Berkshire Hathaway, bringing Warren Buffett’s conglomerate in as a significant new backer and adding a prominent seal of approval to Alphabet’s AI ambitions. Berkshire will receive $5 billion in Class A shares at $351.81 apiece and $5 billion in Class C shares at $348.20, both priced below Monday’s close.

The investment extends a position Berkshire has been building since last year’s third quarter. Last month, the company disclosed it had more than tripled its stake in the Google parent, which at $16.6 billion has become one of its largest common stock holdings.

Alphabet said it plans to raise $30 billion through concurrent public offerings underwritten by investment banks, split evenly between depositary shares tied to mandatory convertible preferred stock and Class A and C common shares. The company also intends to launch a $40 billion at-the-market programme in the third quarter, giving it the flexibility to sell stock gradually over time.

"The company is experiencing strong demand for its AI solutions and services from enterprises and consumers, at levels that are exceeding the company’s available supply," Alphabet said.

Broadcom, the sixth-largest U.S. company by market capitalization, is set to report quarterly results on Wednesday. Semiconductor stocks have rallied in recent weeks on optimism that surging investment in AI infrastructure will continue to boost chipmaker earnings.