(Updates with closing prices)

SINGAPORE, June 18 (Reuters) - Japan's Nikkei share

average touched a four-month high on Wednesday, boosted by a

weaker yen even as investors kept a wary eye on the rapidly

escalating conflict between Israel and Iran.

The Nikkei ended the day up 0.9% at the session's

high of 38,885.15, a level last seen on February 20. The broader

Topix rose 0.8%.

The biggest boost to the Nikkei came from Uniqlo-brand owner

Fast Retailing ( FRCOF ), chip-testing equipment maker Advantest ( ADTTF )

and Switch-maker Nintendo ( NTDOF ), which rose 2%, 1.2%

and 6.6%, respectively.

"Japan remains one of our favoured equity markets," said Ben

Powell, chief APAC investment strategist at the BlackRock

Investment Institute.

"Ongoing shareholder-friendly reforms to boost profitability

support our tactical overweight on Japanese stocks," he said.

"We prefer unhedged equity exposures, given the yen's tendency

to strengthen during periods of market stress."

The Nikkei steadily extended its advance as the day

progressed despite heightened worries among market participants

over the potential for a more direct U.S. military involvement

in the Middle East.

Reuters reported, citing three U.S. officials, that the U.S.

military is deploying more fighter aircraft to the region and

extending the deployment of other warplanes. U.S. President

Donald Trump called for Iran's "unconditional surrender".

The safe-haven yen strengthened 0.2% versus the

U.S. dollar on Wednesday but touched a one-week low earlier in

the session, following a 1.3% slide over the previous three

days.

A weaker Japanese currency tends to boost shares of

exporters, as it increases the value of overseas profits in yen

terms.

"The weaker yen is providing support," said Maki Sawada, an

equities strategist at Nomura Securities.

"A solid floor seems to have formed for the Nikkei, but the

market is cautious about developments in the Middle East and

will be sensitive to any headlines."