* MSCI ex-Japan steady after four consecutive losing days

* Cracks in bull case emerging - BofAML fund manager survey

* Investors fretting over risk of trade war

* Australian, NZ, Canadian dollars knocked down in recent days

By Swati Pandey

SYDNEY, March 21 (Reuters) - A hush settled over financial markets on Wednesday as investors waited to hear how often the Federal Reserve might hike U.S. rates this year, while the currencies of exporting nations were rattled by fears of a full-blown trade war.

MSCI's broadest index of Asia-Pacific shares outside Japan was barely changed after four straight days of losses. E-Mini futures for the S&P 500 were slightly softer.

Japan's Nikkei was closed for a local holiday while Australian shares were up 0.4 percent.

Global shares rallied for all of 2017 but have started this year on the back foot, hit by a combination of factors including the risk of faster rate rises in the United States and alarm over protectionism.

"Cracks in the bull case are starting to emerge," said Michael Hartnett, chief investment strategist at BofAML, citing the bank's March fund manager survey.

"The threat of a trade war returns to the top of the list of tail risks most commonly cited by investors, followed by inflation and a slowdown in global growth," he added.

"Investors have yet to act on these fears, however, as rates and earnings are keeping the bulls bullish."

U.S. President Donald Trump is expected to unveil up to $60 billion in import duties on Chinese goods by Friday. The move comes after Trump imposed tariffs on imported steel and aluminium earlier this month.

Investors are worried Trump's actions could escalate into a full-blown trade war if China and other countries retaliate with similar or harsher measures, threatening global growth.

To add to these concerns, a meeting of finance ministers and central banks of the world's 20 biggest economies this week failed to diffuse the threat.

The so-called G20 agreed only to stand by an ambiguous declaration on trade from 2017 and "recognised" the need for more "dialogue and actions".

TRADE WAR, FED

The currencies of export-heavy nations such as the Australian, New Zealand and Canadian dollars have been knocked down in recent days.

The Aussie fell to a three-month trough of $0.7679 overnight while the kiwi dollar hit the lowest since early January. The Canadian dollar held at $1.3076 from Monday's low of $1.3124, a level not seen since mid-2017.

The Hong Kong dollar eased to a fresh 33-year low of HK$7.8452 to U.S. dollar in early Wednesday trade.

"The last three days has seen the AUD come under pressure as investors have considered Australia's exposure to Asian markets in general and China in particular," said Simon Derrick, chief currency strategist at BNY Mellon.