TOKYO, June 24 (Reuters) - Japanese shares were flat on Thursday as uncertainty over domestic corporate earnings kept investors on the sidelines, while Mercari jumped after the technology startup forecast its first annual net profit. Nikkei share average was flat at 28,875.23, while the broader Topix slipped 0.10% to 1,947.10. “U.S. inflation could stay at high levels, so we will need more data on inflation, wages and employment. And, quarterly earnings will be a few weeks away, the market is running out of trading factors,” Nobuhiko Kuramochi, senior strategist at Mizuho Securities, said. Two Fed officials said a period of high inflation in the United States could last longer than anticipated, a day after Fed Chair Jerome Powell played down rising price pressures. Many hospitality-related shares, which led index’s gains before the Fed meeting outcome, have now succumbed to profit-taking, weighed also by concerns about a spike in COVID-19 cases after the government eased social restrictions last week. West Japan Railway fell 2.7% while department store operators Isetan Mitsukoshi and Takashimaya lost 3.2% and 2.1%, respectively. Sumitomo Forestry shed 0.8% after the company announced a plan to sell new 16 million shares, which amount to 8.7% of its existing shares to raise up to 37.1 billion yen ($334.32 million). Toshiba erased early losses to close 0.1% flat after financial magazine Diamond reported Kioxia Holdings Corp, formerly known as Toshiba Memory, in which Toshiba holds a 40.6% stake, plans to list as early as in September. Some growth shares outperformed after U.S. tech stocks hit a record high overnight. Softbank gained 2.2% following solid gains in U.S. tech shares. Mercari jumped 8.5% after the flea market app operator ramped up its outlook to forecast a net annual profit of 5 billion yen, its first annual profit since its listing in June 2018. Eisai gained 1.5% after the drugmaker said U.S. regulator had granted breakthrough therapy designation to their experimental therapy, lecanemab, for patients with early Alzheimer’s. ($1 = 110.97 yen) Reporting by Hideyuki Sano, Editing by Sherry Jacob-Phillips Our Standards: The Thomson Reuters Trust Principles.