TOKYO – SoftBank Group Corp overtook Toyota Motor Corp on Monday to become Japan's most valuable publicly traded company, ending the automaker's 22-year reign.

On the Tokyo Stock Exchange, SoftBank shares closed at an all-time high on Monday, rising more than 14 percent and boosting the company's market capitalization to 48.8 trillion yen ($301 billion), compared with 45.9 trillion yen for Toyota Motor.

Toyota had retained the top position since December 2003 when it overtook NTT Docomo Inc.

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On the stock market, SoftBank shares have been gaining an upward momentum after news reports that OpenAI, the US artificial intelligence company behind ChatGPT and in which SoftBank is an investor, is preparing an initial public offering.

Meanwhile, automobile stocks have been weighed down by rising crude oil prices.