US STOCKS-Wall St flat amid Ukraine uncertainty

* S&P 500 more than 2 percent from record close

* Investors continue to watch geopolitical tensions

* Intercept, Exact Sciences jump on drug news

* Dow up less than 0.1 percent; S&P, Nasdaq flat (Updates to market open)

By Ryan Vlastelica

NEW YORK, Aug 12 (Reuters) - U.S. stocks were little changed on Tuesday as uncertainty continued to swirl around the tense situation in Ukraine, even as many investors bet that it would not escalate dramatically.

Equities have come under pressure because of the unrest between Russia and Ukraine, with the S&P 500 at one point down about 4 percent from a record closing high hit in late July. The benchmark has recovered some of that decline, and rose over the past two sessions, but it remains more than 2.5 percent below its record, suggesting traders may see bargains in the market.

Futures rose early in the premarket session, but subsequently came off their highs amid ongoing concerns about the region, with Ukraine reporting that Russia had massed 45,000 troops on its border. Russia said a convoy of 280 trucks carrying humanitarian aid had set off for Ukraine, and Western governments warned against using help as a pretext for an invasion.

"The situation seems a bit quieter now, with the aid going in, but it will take a while for this to play out, and this doesn't seem like a time for people to stick their necks out," said James Dunigan, chief investment officer at PNC Wealth Management in Philadelphia.

"It is hard to see the market moving higher in the short term, but long-term investors can still find value and the U.S. economic backdrop continues to be very positive."

Investors remained concerned about the fallout from any escalation in tensions. In Germany, geopolitical anxiety hit economic sentiment in August, the ZEW think tank said, with investor morale dropping to its lowest since December 2012. Market participants also monitored other areas of unrest, including the recent violence in the Gaza Strip and Israel and U.S. air strikes in Iraq.

The Dow Jones industrial average rose 7.93 points or 0.05 percent, to 16,577.91, the S&P 500 gained 0.69 points or 0.04 percent, to 1,937.61 and the Nasdaq Composite dropped 1.67 points or 0.04 percent, to 4,399.66.

Drug companies rallied, with Intercept Pharmaceuticals Inc (NasdaqGS: ICPT - news) soaring 30 percent to $307.25 a day after saying its drug to treat liver disease was effective in mid-stage trials. Exact Sciences rose 7.4 percent to $18.35 after the Food and Drug Administration approved its noninvasive colorectal cancer screening test.

Energy companies were among the weakest of the day. The S&P Energy index fell 0.6 percent, dropping alongside a 0.7 percent fall in crude oil. Anadarko Petroleum fell 1.7 percent to $106.75 while Consol Energy (NYSE: CNX - news) was down 1.6 percent to $39.82. Both were among the top 5 biggest percentage decliners on the S&P 500.

Mobile service provider NII Holdings Inc (NasdaqGS: NIHD - news) 's shares plummeted 65 percent to 22 cents - the stock's biggest one-day decline ever - a day after saying it may have to file for bankruptcy after struggling to compete in Brazil and Mexico. The stock has lost almost 92 percent in 2014. (Editing by Jeffrey Benkoe and Nick Zieminski)