Microsoft and OpenAI on Monday announced a sweeping overhaul of the partnership that has defined the commercial AI era, dismantling key pillars of exclusivity and revenue-sharing that bound the two companies together for years and replacing them with a looser, time-limited arrangement that gives both sides far more freedom to pursue rival relationships. The amended agreement, disclosed simultaneously in blog posts from both companies , marks the most significant restructuring since Microsoft first invested $1 billion in OpenAI in 2019 — and it transforms what was once the most consequential exclusive technology alliance in a generation into something that more closely resembles a strategic but arm's-length commercial relationship. Under the new terms, Microsoft will no longer pay any revenue share to OpenAI when customers access OpenAI models through Azure.…