Alphabet sold $20 billion in bonds in a seven-part offering, tapping the debt market to fund its surging spending on artificial intelligence infrastructure.

Big Tech's appetite for debt is surging, after years of relying on strong cash flows to fund investments.

Alphabet is also planning a debut sterling offering that may include a rare 100-year bond, the tech industry's first since Motorola's 1997 issuance, according to media reports.

Big Tech's pivot to the bond market, however, has raised investor concerns as payoffs have not kept pace with the huge AI spending from US tech giants, while businesses adopting the technology have so far seen limited productivity gains.

Capital expenditures by Alphabet, Microsoft, Amazon.com, and Meta Platforms are expected to total at least $630 billion this year, with most of the spending focused on data centers and the AI chips that power them.

The seven tranches of Alphabet's dollar notes mature every few years, from 2029 through 2066, according to a regulatory filing on Tuesday.

Some analysts said Big Tech's greater use of debt reflects a pivot from asset-light models toward long-term infrastructure.

"Century bonds are usually the preserve of governments or regulated utilities with very predictable cash flows, so this deal shows that, at least for now, investors are willing to take on very long-dated risk tied to AI investment," said Lale Akoner, global market analyst at eToro.

Oracle had also disclosed a $25 billion note sale on February 2 in a securities filing.

The AI hyperscalers - a group that also includes Oracle - issued $121 billion in US corporate bonds last year, according to a January report by BofA Securities.

The announcement came a month after Alphabet unveiled new features for its Google AI users. The new AI system, called Personal Intelligence, will deliver personalized search results based on the content of emails and images in the Google Photos gallery, the company announced on Thursday in its official blog.

“With Personal Intelligence, recommendations don’t just match your interests, they fit seamlessly into your life. You don’t have to constantly explain your preferences or existing plans; it selects recommendations just for you, right from the start,” wrote Robby Stein, VP of Product at Google Search, in the blog entry.

According to the release, the function will be available only to American Google AI Pro and AI Ultra subscribers.