Nikkei logs six-week closing high as Micron forecast lifts chip stocks

By Satoshi Sugiyama

TOKYO, Oct 1 (Reuters) - Japan's Nikkei share average posted its highest close in more than six weeks on Thursday, after robust earnings from Micron Technology fuelled optimism over AI-related investment.

The Nikkei 225 Index .N225 rose 3.3% to close at 68,956.72, its highest since August 17. The broader Topix .TOPX edged 0.57% higher to 4,131.98.

Micron MU.O forecast quarterly revenue above estimates and said customers had increased commitments under its long-term supply agreements to $32 billion, signalling unabated demand for AI memory chips.

Chip-related shares led gains on the Nikkei, with chip inspection equipment maker Lasertec 6920.T surging 11.14% to a two-month high.

Semiconductor testing equipment maker Advantest 6857.T jumped 9.78%, electronic component maker Murata Manufacturing 6981.T rallied 8.43% and memory chipmaker Kioxia 285A.T climbed 5.55%.

Still, some analysts cautioned against reading too much into the rally in AI-related shares.

"Earnings from companies such as Micron Technology are certainly positive factors, but we need to bear in mind the possibility that any gains may be driven by one-off earnings-related news," said Wataru Akiyama, equity strategist at Nomura Securities.

Market breadth was mixed, with 108 of the Nikkei's 225 names closing higher and 116 lower.

Mixed business confidence among manufacturers and non-manufacturers in the Bank of Japan's quarterly Tankan survey, along with comments from a government representative in the BOJ's September meeting summary that were seen as cautious on further rate hikes, tempered expectations for a back-to-back rate increase this month.

Rate-sensitive banking .IBNKS.T and insurance .IINSU.T shares, which tend to benefit from higher interest rates, fell 2.44% and 2.31%, respectively.

Oil and coal .IPETE.T shed 2.97% as recovering crude exports from the Middle East and a surprise rise in US inventories eased supply concerns and pushed oil prices lower.

The largest losers were oil refiner Idemitsu Kosan 5019.T, down nearly 4%, followed by Daiichi Life Group 8750.T, 3.12% lower, and Mitsubishi UFJ Financial Group 8306.T, which lost 3.08%.