Google’s parent company, Alphabet, has announced plans to raise up to $80bn (£59bn) in equity to finance major investments in artificial intelligence infrastructure, intensifying debate over the financial sustainability of the AI boom.

The fundraising effort—described by analysts as the largest equity raise on record, includes a $10bn share sale to US investment firm Berkshire Hathaway, which was led until last year by Warren Buffett.

Alphabet, which develops the Gemini AI system that has been steadily gaining market share in the chatbot space, said the funds will be used to expand its “world-class AI compute infrastructure” in response to surging global demand.

It said, “AI is driving an expansionary moment for Alphabet. 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. By scaling its investments, the company seeks to expand its foundational infrastructure to support the significant growth opportunity ahead.”

In its filing, Alphabet said half of the $80bn would go toward “scaling AI infrastructure and global compute”, while the remaining $40bn is allocated to “an administrative change to how it meets tax obligations associated with vesting of employee equity awards”.

The fundraising package includes a $30bn initial raise, alongside the $10bn investment from Berkshire Hathaway, as well as a $40bn flexible drip-feed facility that can be deployed gradually over time and is not specifically tied to AI investment.