TOKYO, May 12 (Reuters) - Japan's Nikkei share average hit its highest in 1-1/2 years on Friday, led by gains in chip-related heavyweights, as investors cheered announcements of domestic firms' shareholder returns at the peak of the earnings season.

The Nikkei rose to as high as 29,408.06, its highest since Nov. 2021, before ending the morning session up 0.80% at 29,359.43. The index is set to rise 0.69% for the week.

The broader Topix rose 0.56% to 2,094.72 and is poised to gain 0.87%.

"Corporate outlook was not necessary all good. We saw some positive outcome but also there were disappointments," said Seiichi Suzuki, chief equity market analyst at Tokai Tokyo Research Institute.

"But many companies have announced share buybacks and other measures to give returns to shareholders. That raised investor sentiment and boosted the market."

A slew of Japanese firms have announced share buyback plans and more dividend payouts during the earnings season.

Notable examples are the nation's top trading houses, including Mitsubishi Corp, which flagged continued rewards to shareholders this financial year - either with hikes to dividends or stock buybacks or both.

Mitsubishi shares rose 0.22% on Friday and have posted a near-7% gain so far this month.

Heavyweight Tokyo Electron Ltd cut early losses to jump 2.23% even as Japan's leading maker of semiconductor manufacturing tools flagged a lower-than-expected annual operating profit.

Its peer Advantest Corp gained 2.64%.

Bucking the trend, SoftBank Group Corp fell 2.98% and weighed on the Nikkei the most after the Japanese technology investor posted an annual loss that was more than three times as big as market expectations.

Sharp Corp tanked 7.37% after the electronics maker reported a surprise $1.9 billion loss on writedowns of its panel display business and other assets. (Reporting by Junko Fujita; Editing by Varun H K)