Microsoft Corp. and OpenAI finalized a new agreement in a long-negotiated partnership, removing a layer of uncertainty for both companies’ investors and paving the way for the ChatGPT maker to restructure as a for-profit business. Under the revised pact, Microsoft will get a 27% ownership stake in OpenAI worth about $135 billion, the companies said in a statement Tuesday. In addition, Microsoft will have access to the artificial intelligence startup’s technology until 2032, including models that...