Microsoft built a multi-billion-dollar relationship with OpenAI. Now it is quietly teaching its salespeople to sell around it.
At its Build 2026 conference in early June, Microsoft unveiled seven new in-house models under the MAI banner, short for Microsoft AI. The flagship, MAI-Thinking-1, runs on 35 billion parameters with a 256K context window. The pitch to enterprise customers: it does what GPT and Claude do, at a fraction of the cost.
That is not a small claim. Microsoft says its MAI models can deliver up to 10 times better cost efficiency in tuned enterprise workloads compared to competing models. The company also says MAI-Thinking-1 can match or outperform GPT-5.5 and Claude Opus 4.6 on key benchmarks, particularly in coding tasks measured by SWE-Bench Pro.
From partner to competitor, sort of
Microsoft holds a stake in OpenAI valued at roughly $135 billion as of late 2025.
