TOKYO - Japan’s Nikkei share average topped 67,000 for the first time on June 1, powered by AI-related shares, as start-up investor SoftBank Group overtook Toyota Motor to become the country’s most valuable company.The Nikkei climbed 1.1 per cent to enter the midday recess at 67,038.24, after pushing as high as 67,231.28.SoftBank was by far the biggest support for the index, jumping 10.3 per cent to contribute 618 points of the Nikkei’s total 709-point rise.The company’s market capitalisation swelled to around 47.2 trillion yen (S$378 billion), while Toyota’s shrank to around 45.7 trillion yen after the stock slid 4.8 per cent on June 1.At the weekend, SoftBank pledged some €75 billion (S$111.6 billion) over five years to build up artificial intelligence infrastructure in France.The split between tech shares and the rest of the market was clear from the performance of the broader Topix, which sagged 0.2 per cent.Both the Nikkei and Topix had notched all-time highs on May 29 on optimism over a near-term peace deal in the Middle East, but the fresh week began with Washington and Tehran still appearing to differ on significant issues.“Given the current expectations for expanding demand for AI servers, buying interest is spreading to AI-related stocks that had been lagging behind”, such as electronic components-maker Murata Manufacturing, said Maki Sawada, a strategist at Nomura Securities.Shares of Murata surged 14.1 per cent to be the Nikkei’s biggest percentage risers.At the same time, “we’re in a situation where concerns about overvaluation are deep-rooted”, particularly with uncertainty around the Middle East still high, Sawada said.Among the Tokyo Stock Exchange’s 33 industry groups, eight rose, led by a 4.3 per cent jump in IT firms. Auto shares were among the worst performers, down 4.2 per cent.Even in the Nikkei, only 73 of its 225 components rose, versus 152 that fell.Not all chip-related shares advanced, with Advantest retreating 2.2 per cent and Fujikura down 3.6 per cent.Mitsubishi Motors was the biggest percentage decliner, tumbling 9.1 per cent. Alliance partner Nissan was another standout loser, declining 7.2 per cent. REUTERS