Perplexity AI, the artificial-intelligence search engine startup, is in the final stages of raising $500 million in funding at a $9 billion valuation, a source familiar with the situation told CNBC.

The startup competes against the likes of Google and ChatGPT-maker OpenAI. Perplexity most recent valuation was $3 billion in June. Institutional Venture Partners, a Bay Area-based firm, is leading the new round, according to the source, who requested anonymity since the funding is not yet public.

Perplexity started the year with a roughly $500 million valuation. Since then, the company has continued to attract investor interest amid the generative AI boom, raising four funding rounds so far this year.

Last week, OpenAI launched a search feature within ChatGPT, its viral chatbot, that positioned it to better compete with Perplexity, as well as leading search engines like Google and Microsoft’s Bing. OpenAI’s search feature offers up-to-the-minute sports scores, stock quotes, news, weather and more, powered by real-time web search and partnerships with news and data providers, according to the company.

Despite the AI boom, Perplexity has been embroiled in controversy due to accusations of plagiarizing content from media outlets. The New York Times last month sent Perplexity a “cease and desist” notice, claiming that the startup scrapes the news outlet’s content to generate answers. Perplexity has denied the allegations.

In July, Perplexity debuted a revenue-sharing model for publishers. Any time a user asks a question and Perplexity generates ad revenue from citing an article in its answer, Perplexity will share a percentage of that revenue with the publisher, the company said.

Media outlets and content platforms including Fortune, Time, Entrepreneur, The Texas Tribune, Der Spiegel and WordPress were among the first to join the company’s “Publishers Program.” Dmitry Shevelenko, Perplexity’s chief business officer, told CNBC in a July interview that if three articles from one publisher were used in one answer, the partner would receive “triple the revenue share.” Perplexity worked on its revenue-sharing model since January, and the company’s goal is to have 30 publishers enrolled by the end of the year, Shevelenko said.

Perplexity’s app has been downloaded more than 2 million times, and it answers more than 230 million queries a month, the company said in August. U.S. queries have increased eightfold in the past year, according to a pitch deck for potential advertisers that was viewed by CNBC.

The Wall Street Journal was first to report on the new funding round.

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