Google and Microsoft are rivals, backers and suppliers to the same AI labs

Anthropic's IPO filing and Microsoft's latest earnings, both published this week, show how tightly Google and Microsoft are tied to the AI labs they also compete with. Microsoft said on Wednesday that it booked $10 billion in revenue from OpenAI in the quarter ended September 30.

The disclosures matter because the same companies appear as investor, cloud supplier, sales channel and rival in each deal. That makes it harder to tell who depends on whom.

Microsoft's $10 billion from OpenAI

According to TechCrunch, the $10 billion came from commercial arrangements, including revenue-sharing payments, and was disclosed in a regulatory filing. That is nearly 11% of Microsoft's total quarterly revenue of $92.3 billion.

OpenAI also owed Microsoft $7.2 billion in receivables at the end of September, up from $6 billion at the end of June, TechCrunch reported. TechCrunch noted it is unclear how much of the revenue came from revenue sharing and how much from Azure cloud services.

Microsoft's ownership stake in OpenAI fell from about 25% in June to 24% in September, according to the same report. Microsoft did not say why.

Anthropic's filing names Google and Microsoft

Anthropic made its IPO prospectus public on Monday, October 26. NPR reported that the filing is for a listing under the ticker ANT, which reports have said could value the company at between $1.5 trillion and $2 trillion.

CNBC reported that the only two competitors Anthropic names in the prospectus are OpenAI and Google. Google is also an investor. Invezz reported that Google said in April it plans to invest $40 billion in Anthropic.

The filing also says Anthropic relies on Microsoft, Amazon, Google and Broadcom for computing power. According to CNBC, Anthropic describes those relationships as creating "dependencies and potential vulnerabilities."

Anthropic also said it pays fees to Microsoft, Amazon and Google under a joint go-to-market arrangement, CNBC reported. The aim is to gain a direct relationship with customers.

Microsoft's own Anthropic exposure

Microsoft announced plans in November 2025 to invest $5 billion in Anthropic, CNBC reported. In May, Anthropic said it had raised money at a $965 billion valuation. Weeks later, Microsoft disclosed a $3.2 billion gain on its stake.

Invezz, citing the SEC filing, reported that Anthropic committed to spend at least $44.9 billion with Microsoft between November 2026 and May 2033. The original November 2025 agreement had been modified since, according to the same report.

TechCrunch noted that Anthropic also runs on Azure, even as Microsoft competes with both labs. TechCrunch described Microsoft as one of the largest cloud providers that also holds stakes in the two biggest AI labs.

Why it matters

Investors in the Anthropic IPO will be buying into a company whose largest suppliers, sales partners and shareholders are also its competitors. The prospectus itself flags this as a risk.

For Microsoft, the OpenAI figure shows how much of its revenue depends on one customer that is increasingly free to shop elsewhere. TechCrunch reported that Microsoft ended OpenAI's exclusive cloud arrangement in October 2025, in exchange for an additional $250 billion Azure commitment from OpenAI.

CNBC reported earlier this year that gains on stakes in Anthropic and OpenAI have inflated Big Tech earnings. Those gains are on paper and do not reflect underlying business growth, CNBC said.

What happens next

Anthropic's debut was likely to be pushed to after the November US midterm elections, Reuters previously reported, citing sources. Wikipedia lists a November 2026 listing as the plan, though Anthropic has not given a date in the sources reviewed here.

OpenAI confidentially filed for an IPO in June and is expected to list by early 2027, according to media reports cited by Reuters. Both listings would put the Google and Microsoft ties under closer public scrutiny.