(Updates to closing prices)

By Satoshi Sugiyama

TOKYO, July 27 (Reuters) - Japan's Nikkei share average

ended Monday's session higher, helped by a fall in oil prices

after a halt in U.S. attacks on Iran, while investors stayed

cautious before major earnings due this week.

The benchmark Nikkei rose 0.5% to close at 64,931.19

after fluctuating between gains and losses. The broader Topix

rose 1.37% to 4,066.07.

The U.S. suspended its bombing campaign on Iran after nearly

two weeks of heavy airstrikes, while a senior Iranian official

told Reuters Tehran would also halt its own attacks as long as

Washington did the same. Oil prices fell more than 6% on Monday

on expectations of a diplomatic off-ramp.

"Reduced concern over higher crude prices should support

Japanese shares overall, while buybacks are also expected in

stocks that had seen an increasingly corrective tone through

last week," said Takayuki Miyajima, senior economist at Sony

Financial Group.

"However, with major U.S. cloud companies due to report

earnings this week, investors may be reluctant to aggressively

chase the upside as they assess capital spending plans and the

monetisation of AI investment," he said.

Investors are focused on a busy week of earnings

announcements in the U.S. and Japan, as well as central bank

decisions.

In Tokyo, chip-testing equipment maker Advantest ( ADTTF ) is

due to report earnings on Wednesday, while memory chipmaker

Kioxia ( KXHCF ) is scheduled to report on Friday.

Market breadth was positive, with 194 advancers on the

Nikkei 225 against 31 decliners.

Software testing and quality assurance services provider

Shift was the top percentage gainer on the index,

rising 9.32%, followed by consulting services provider

BayCurrent ( BYCRF ), up 8.95%, and Shiseido ( SSDOF ), a global

cosmetics and skincare company, which rose 7.62%.

Shares of Shin-Etsu Chemical ( SHECF ) slid 8.3%, making the

silicon and chemical products maker the Nikkei's biggest

percentage loser, after its full-year consolidated net profit

outlook undershot market expectations. It was the stock's

steepest percentage loss since January.

Optical fibre producer Fujikura ( FKURF ) lost 5.83% and

SoftBank Group, a tech investment conglomerate, shed

3.07%.