* White House failure on healthcare raises worries over tax reform
* Dollar skids to 4-month low
* Safe havens such as gold, bonds, yen gain
* Oil dips toward $50 on doubts over output cut (Updates to close of U.S. trading)
By Saqib Iqbal Ahmed
NEW YORK, March 27 (Reuters) - Stocks, the dollar and U.S. long-dated Treasury yields steadied after sharp drops on Monday, as investors hoped U.S. President Donald Trump will be able to bolster the economy despite a defeat over healthcare reform.
Trump's failure to rally enough support from his own party, - which controls both houses of the U.S. Congress, to repeal and replace Obamacare spurred a rush to safe-haven assets such as gold, the Japanese yen and the Swiss franc before nerves steadied.
A dip in risk appetite also dominated Asian and European stock markets, and MSCI's all-country world equity index was down 0.11 percent. The index, which fell to a near two-week low after Wall Street stocks hit their lowest levels in about six weeks at the open, recovered ground as major U.S. stock indexes trimmed losses.
The Nasdaq Composite finished the day positive, while the Dow Jones Industrial Average ended the day down 0.22 percent, its eighth straight day of declines.
"The market is still cautiously optimistic that the Trump White House will be able to push through many of their pro-business policies, and I think a lot of people are hopeful the Trump rally can continue through at least the middle of the year," said Jake Dollarhide, chief executive officer of Longbow Asset Management in Tulsa, Oklahoma.
The S&P 500 lost 2.39 points, or 0.10 percent, to close at 2,341.59 and the Nasdaq added 11.64 points, or 0.2 percent, to end at 5,840.37.
European shares were hit by losses among miners and banks. Europe's broad FTSEurofirst 300 index closed down 0.37 percent at 1,479.05.
The U.S. dollar slipped, briefly falling to its lowest since November against a basket of currencies, as investors lost confidence in prospects for a U.S. fiscal spending boost under the Trump administration.
The dollar index had risen to a 14-year high near 104.00 in early January when expectations for inflation-boosting stimulus under the Trump presidency were at their peak. The index was down 0.42 percent at 99.212.
The weaker dollar helped boost gold. Spot gold was up 0.87 percent at $1,254.66 an ounce, after hitting a 1-month high of $1,261.03 an ounce earlier in the session.
U.S. long-dated Treasury yields fell to one-month lows, knocked by growing uncertainty about whether the Trump administration could deliver on its campaign promise to bolster the economy.
In late trading, benchmark 10-year note price gained 7/32 to yield 2.3764 percent, down from Friday's 2.4 percent. Yields earlier fell to 2.348 percent, their weakest level in one month.
U.S. 30-year bond prices rose 9/32, yielding 2.9848 percent. Earlier, yields slid to 2.96 percent, their lowest since Feb. 28.
"The recent hiccup on the policy front casts serious doubt on the administration's ability to push forward its ambitious policy agenda," said Bruno Braizinha, interest rates strategist at Societe Generale in New York.
Oil, meanwhile, resumed its slide as investors remained uncertain whether producing nations would extend an OPEC-led output cut beyond the end of June in an effort to reduce a global glut of crude.
Brent crude settled down 5 cents, or 0.1 percent, at $50.75 a barrel, and U.S. crude settled down 24 cents, or 0.5 percent, at $47.73.
Additional reporting by Chuck Mikolajczak and Gertrude Chavez-Dreyfuss in New York and Yashaswini Swamynathan in Bengaluru; Editing by Nick Zieminski and Dan Grebler