Microsoft recently disclosed that the majority of its AI business revenue originates from OpenAI. Microsoft stated in regulatory filings that it generated $24.1 billion in revenue from OpenAI over the year ending in June. Microsoft CEO Satya Nadella has indicated that the company's AI business annual revenue is expected to reach $37 billion by the end of the March quarter. When Microsoft announced its fourth-quarter results last week, it did not update the total AI sales figures. The disclosure shows that in the most recent fiscal year, OpenAI accounted for more than half, and likely around 70%, of Microsoft's AI sales, highlighting Microsoft's significant reliance on this partner.