OpenAI said late Wednesday that it hired Fidji Simo, the chief executive of Instacart, to take on a new role running the artificial intelligence company’s business and operations teams.

In a blog post, Sam Altman, OpenAI’s chief executive, said he would remain in charge as the head of the company. But Ms. Simo’s appointment as chief executive of applications would free him up to focus on other parts of the organization, including research, computing and safety systems, he said.

“We have become a global product company serving hundreds of millions of users worldwide and growing very quickly,” Mr. Altman said in the blog post. He added that OpenAI had also become an “infrastructure company” that delivered artificial intelligence tools at scale.

“Each of these is a massive effort that could be its own large company,” he wrote. “Bringing on exceptional leaders is a key part of doing that well.”

Ms. Simo, a member of OpenAI’s board, will oversee sales, marketing and finance. She will report to Mr. Altman.

OpenAI, which ignited a frenzy over A.I. with its ChatGPT chatbot, has grown rapidly and juggled multiple initiatives — sometimes unsuccessfully. The San Francisco company has steadily released new A.I. models and products, including systems that can “reason.” In March, it completed a $40 billion fund-raising deal, led by the Japanese conglomerate SoftBank, that valued it at $300 billion and made it one of the most valuable private companies in the world.