AI start-up Perplexity has made an unexpected $34.5bn takeover offer for Google’s Chrome, the world’s most popular web browser.

In a letter to Alphabet chief executive Sundar Pichai, Perplexity said moving Chrome to an independent operator committed to user safety would benefit the public.

However, technology investor Heath Ahrens described the bid as a “stunt”, claiming it was far below Chrome’s real value and unlikely to be accepted. Chrome has more than three billion users worldwide, and Google has not indicated it is for sale.

The BBC has contacted Google for comment. The company has previously argued that spinning off Chrome would harm consumers and security.

Google faces mounting antitrust scrutiny in the US, with a federal court ruling expected this month that could order the break-up of its search business. The company has said it would appeal such a decision.

Perplexity said it would keep Google as Chrome’s default search engine, while allowing users to change settings, and pledged to maintain Chromium, the open-source platform supporting Chrome and other browsers.

The start-up, valued at about $18bn in July, did not disclose funding plans for the deal. Tomasz Tunguz of Theory Ventures estimated Chrome’s true value could be “ten times more” than Perplexity’s offer.

Perplexity, a growing rival to OpenAI’s ChatGPT and Google’s Gemini, recently launched its own AI-powered browser, Comet.