Tokyo, June 1 (Jiji Press)--SoftBank Group Corp. became the most valuable Japanese company on Monday, ending Toyota Motor Corp.'s 22-year reign. On the Tokyo Stock Exchange, SoftBank Group shares jumped about 14 pct, boosting the company's market capitalization to 48,784.8 billion yen, above Toyota's 45,892.3 billion yen. The milestone comes as the stock market has recently been driven by SoftBank Group and other technology issues, including those related to artificial intelligence and semiconductors. Meanwhile, automobile stocks have been weighed down by rising crude oil prices. SoftBank Group's stock price has been rising on news that OpenAI, the U.S. developer of ChatGPT, in which the Japanese technology investor has a stake, is preparing an initial public offering, as well as on a rosy earnings report from its British chip designer unit, Arm Holdings PLC. Adding to the positive momentum, the group announced on Sunday that it would invest up to 75 billion euros to build AI data centers in France. In May, SoftBank Group reported a consolidated net profit of 5,002.2 billion yen for fiscal 2025, setting a record high for a Japanese company. The record profit was seen as "a factor justifying the AI boom," said an official at a Japanese brokerage firm. SoftBank Group has been accelerating investments related to AI in recent years, including plans to increase its investment in OpenAI to 64.6 billion dollars. In the United States, the Japanese company is promoting a project called Stargate to build AI data centers for OpenAI. END [Copyright The Jiji Press, Ltd.]