TOKYO, Sept 28 (Reuters) - Japanese stocks gained on Monday, tracking Wall Street's tech rally in the previous session, with sentiment aided by an appetite for stocks that were set to go ex-dividend this week.

The benchmark Nikkei share average rose 0.72% to 23,371.70 by the midday break and the broader Topix gained 0.78% to 1,646.93. All but four of the 33 sector sub-indexes on the Tokyo exchange traded higher.

Investors took cues from Wall Street's positive finish on Friday when main indexes gained more than 1%, while in Japan, analysts cited demand for index futures by index and mutual funds lifting sentiment.

But U.S.-China tensions capped gains after reports the U.S. had sent letters informing companies that suppliers of certain equipment to China's Semiconductor Manufacturing International Corporation must apply for individual export licenses.

Amid the tech-related dispute between the two nations, chipmaker Kioxia Holdings Corp postponed plans for what would have been Japan's largest initial public offering this year.

This triggered a sell-off in Toshiba Corp stocks, which had intended to return most of the IPO proceeds to shareholders, dropping more than 8% in early session before retracing some losses to trade 3.15% lower by the recess.

Other semi-conductor shares also declined. Sumco Corp fell 1.02%, while Tokyo Electron and Advantest Corp slid 1.41% and 1.75%, respectively.

Stocks that outperformed included Nitori Holdings, which climbed 0.61% after the interior goods company announced upward revisions to earnings forecasts.

Elsewhere, the Mothers Index of start-up firm shares fell 0.41%. (Reporting by Eimi Yamamitsu; editing by Uttaresh.V)