(Updates as of 0934)

By Kevin Buckland, Amanda Cooper and Alden Bentley

NEW YORK/LONDON/TOKYO, March 27 (Reuters) - Global

shares rose on Wednesday, nudged higher by a rally in Japanese

stocks as the yen sagged to its weakest since 1990, while the

dollar held mostly steady in a holiday-shortened week that ends

with a key reading on U.S. inflation.

The yen, which has lost more than 7% in value against the

dollar this year already, weakened to as far as 151.975 to the

dollar, prompting Japan's three main monetary authorities to

hold an emergency meeting on Wednesday to discuss the currency.

Market participants took this as a signal officials were

ready to intervene in the market to stop what they described as

disorderly and speculative moves in the yen.

"The news this morn was the Japanese yen. They're always

concerned, even well before this for so many years, about hedge

funds coming in and taking advantage of the yen," said Quincy

Krosby, chief global strategist at LPL Financial, in Charlotte,

NC. "So they typically come out with the warning to notify the

market that 'we could come in and thwart your ambition in our

currency market'."

The yen has been sliding despite the Bank of Japan's first

interest rate hike for 17 years last week, as traders expect

very gradual tightening and possible delays to long-expected

Federal Reserve easing.

BOJ board member Naoki Tamura reinforced the dovish outlook

on further tightening on Wednesday, saying the central bank

should "move slowly but steadily toward policy normalisation".

Wall Street's main indexes rose at the open as chipmakers

and growth stocks rebounded in light trading. The S&P 500

gained 29.63 points, or 0.57%, and the Nasdaq Composite

gained 64.40 points, or 0.39%.

The Nikkei closed up 0.9%, although equities trading

elsewhere was more subdued. MSCI's gauge of stocks across the

globe rose 2.88 points, or 0.37%, to 781.41,

while Europe's STOXX 600 index rose 0.12%.

"It's choppy, directionless trading, and there's a good

reason for that: we've hit that time of the quarter when

rebalancing flows are impacting the market," said Tony Sycamore,

a strategist at IG.

Another reason is that two key events - the release of the

U.S. Federal Reserve's favoured inflation indicator and public

comments from Fed Chair Jerome Powell - come on Friday, when

most markets are closed for a holiday, he added.

DOLLAR/YEN IN FOCUS

Against the Japanese yen, the dollar weakened 0.16%

at 151.3. The dollar index was up 0.13% at 104.42, just

below Friday's five-week high of 104.49, while the euro

was down 0.15% at $1.0814.

"If there's any kind of intervention, it only has a

significant lasting impact if the direction of travel has

already begun to turn," Guy Miller, chief market strategist at

Zurich Insurance Group, said.

"We've seen intervention in many countries over the years,

but usually, while that can work in the very short term, you

need to see the currency itself fundamentally change direction,

and then policy intervention can reinforce that or exacerbate

the move," he said.

U.S. 10-year Treasury yields were down slightly

at 4.222%.

Traders are trying to gauge which of the big central banks -

the Fed, ECB or Bank of England - will be first to cut rates

this year.

Meanwhile, Sweden's Riksbank left interest rates unchanged

but indicated it was likely to start easing monetary policy in

either May or June.

Spot gold added 0.42% to $2,187.69 an ounce as it

continued to search for a short-term floor following its surge

to a record $2,222.39 last week. U.S. gold futures gained

0.43% to $2,186.60 an ounce.

Cryptocurrency bitcoin gained 2.17% at $71,330.00.

Oil fell for a second day after a report that crude

stockpiles surged in the U.S., the world's biggest oil user, and

on signs major producers are unlikely to change their output

policy at a technical meeting next week.

Brent crude futures for May fell 0.35% to $85.95 a

barrel. The May contract is set to expire on Thursday and the

more actively traded June contract eased 0.61% to

$85.11. U.S. crude lost 0.36% to $81.33 a barrel.

(Additional reporting by Dhara Ranasinghe in London and Kevin

Buckland in Tokyo; Editing by Muralikumar Anantharaman, Kim

Coghill, Jane Merriman, Andrea Ricci, William Maclean)