US stocks managed to hold small gains after toggling in and out of positive territory Thursday, as market boost from upbeat corporate earnings was offset by renewed concerns over Ukraine.

The Dow Jones Industrial Average stood nearly unchanged at 16, 501.65. The S&P 500 gained 3.22 points, or 0.17 percent, to 1,878. 61. The Nasdaq Composite Index jumped 21.37 points, or 0.52 percent, to 4,148.34.

Corporate earnings have pleased investors with encouraging results so far this week when roughly one third of the S&P 500 companies are expected to post their quarterly earnings.

Shrugging off a pause on the previous trading session, the market opened up, as a pair of encouraging earnings from tech giants comforted investors who had been spooked by recent sell-off on high-flying momentum stocks.

Apple's shares surged 8.20 percent to 567.77 US dollars apiece after the world's most valuable company by market capitalization released late Wednesday second fiscal quarter results that beat analyst expectations, and announced a stock split plan.

Social networking site Facebook reported late Wednesday a 72- percent increase in first-quarter revenue that easily topped market forecast. However, Facebook's shares closed 0.80 percent lower to 60.87 dollars apiece after fluctuating.

Dow component Caterpillar also posted better-than-expected quarterly results and lifted its full-year profit outlook Thursday. Shares of the construction and mining equipment manufacturer rose 1.84 percent to 105.28 dollars per share.

However, another two Dow components 3M, a diversified manufacturer, and wireless provider Verizon Communications, fell shy of market consensus on their profits, limiting gains of the blue-chip Dow index.

Corporate earnings continued to roll out after the closing bell, with Microsoft releasing its quarterly earnings and revenues that exceeded analysts' forecasts whereas Amazon.com surpassing market expectations on its revenue side while matching market estimates on its earnings side.

Despite upbeat earnings, investors seemed more likely to stay on the sidelines amid escalating tensions in Ukraine, which put a damper on the market.

As for other corporate news, medical device company Zimmer Holdings said it agreed to acquire orthopedic products company Biomet for 13.35 billion dollars. In response, Zimmer's shares soared 11.50 percent to 101.97 dollars apiece.

Economic data from the country came out mixed in the day, providing no clear direction to the market. New orders for manufactured durable goods in March rose 2.6 percent to 234.8 billion dollars, the US Commerce Department said Thursday. The fresh figure beat market expectations.

Moreover, the number of Americans who initially applied for jobless benefits last week added 24,000 to a seasonally adjusted 329,000, said the Labor Department.

In other markets, the dollar erased earlier gains and slipped against most major currencies on Thursday on renewed market worries over Ukraine despite strong US durable goods data.

Earlier in the day, Ukrainian Interior Ministry said five " separatist militants" were killed during "counter-terror" actions at three checkpoints set up by a pro-Russia militia outside the city of Slavyansk.

In late New York trading, the euro rose to 1.3825 dollars from 1.3816 dollars of the previous session. The greenback bought 102. 34 Japanese yen, lower than 102.42 yen in the previous session.

Oil prices increased on tensions between Ukraine and Russia and upbeat US economic data.

Light, sweet crude for June delivery moved up 50 cents to settle at 101.94 dollars a barrel on the New York Mercantile Exchange, while Brent crude for June delivery gained 1.22 dollars to close at 110.33 dollars a barrel.

Gold futures on the COMEX division of the New York Mercantile Exchange rose to the highest level since April 17 on safe-haven demand.

The most active gold contract for June delivery rose 6 dollars, or 0.47 percent, to settle at 1,290.6 dollars per ounce.