* U.S. stimulus bill awaited, jobless figures dreaded

* Nikkei falls 4%

* Dollar jumps vs Aussie and kiwi

* Asian stock markets: https://tmsnrt.rs/2zpUAr4

By Tom Westbrook

SINGAPORE, March 26 (Reuters) - A two-day equities rally lost momentum on Thursday, and investors sold riskier currencies, as stimulus negotiations dragged on in Washington and investors fretted over a likely spike in U.S. jobless claims.

MSCI's broadest index of Asia-Pacific shares outside Japan wobbled either side of flat. Japan's Nikkei slumped 4% and U.S. stock futures fell 1%.

The dollar climbed around 1% against the Australian and New Zealand dollars and the yen rose 0.4% against the dollar as investors sought shelter.

"We are not out of the woods just yet," said Stephen Daghlian, at brokerage CommSec in Sydney. "There are plenty of risks in the next couple of weeks."

First among them are initial jobless claims in the United States due at 1230 GMT, with forecasts in a Reuters poll ranging from 250,000 claims all the way up to 4 million.

U.S. Federal Reserve Chairman Jerome Powell is also due to appear on NBC television around 1100 GMT.

The Fed's promise of unlimited bond buying has eased some of the virus-driven financial stress this week. But Powell is also likely to be asked about the real economy, and the apparent divide between health officials and President Donald Trump as to how quickly the country can return to work.

Meanwhile, as Senate leaders in United States hoped to vote on the stimulus package late in the Washington night, markets' patience and optimism are beginning to waver.

"There has been so much stimulus thrown at this," said Jun Bei Liu, portfolio manager at Tribeca Investment Partners in Sydney.

"But the positivity related to it is really just sentiment," she said. "A lot of companies have withdrawn earnings guidance...these are still ahead of us. We don't know how bad it could be."

Hong Kong's Hang Seng was down 0.5% by mid-morning while regional trade was mixed. Indexes in China posted meagre gains and Australia, Indonesia and Thailand advanced.

JOBLESS CLAIMS TO TEST BOUNCE

The money at stake in the stimulus bill amounts to nearly half of the $4.7 trillion the U.S. government spends annually.

But it also comes against a backdrop of bad news as the coronavirus spreads and more signs of economic damage.

Singapore's economy suffered its biggest contraction in a decade in the first quarter, data showed on Thursday, as the coronavirus pandemic prompted the city-state to cut its full-year GDP forecast and plan for a deep recession.

Spain's coronavirus death toll has overtaken China's and a total of 21,221 people have died globally.