OpenAI has closed a $40 billion funding round that values the artificial intelligence company at $300 billion, according to people familiar with the deal. The transaction ranks among the largest private capital raises ever reported in the tech sector.

The latest round underscores continued investor appetite for artificial intelligence firms, even as questions persist about the cost of building and scaling advanced models. The company has become one of the most closely watched players in the industry as demand for generative AI tools continues to grow.

A valuation of this size places OpenAI among the most highly valued private companies in the world. The new funding is expected to give the company more room to expand its computing capacity, research efforts, and commercial products.

Reuters said the deal had been completed based on information from people familiar with the matter. OpenAI did not immediately publicly detail the terms of the transaction in the report.