* Investors watching situations in Greece, Ukraine
* S&P 500 coming off record closing high
* Celsus shares plummet after drug fails study
* Dow down 24 pts, S&P down 4.25 pts, Nasdaq up 2.25 pts (Updates prices)
By Ryan Vlastelica
NEW YORK, Feb 17 (Reuters) - U.S. stock index futures pointed to a quiet open on Tuesday, the first trading session after the S&P 500 closed at a record high, although investors continued to watch the uncertainty over a Greek debt deal and a fragile Ukraine truce.
Equities have been in an uptrend lately, with major indexes notching a second week of solid gains last week. Much of the advance came on signs of progress for the debt deal in Greece, as well as reduced tension between Russia and Ukraine.
Both situations appeared less stable over the long weekend when U.S. stock markets were closed Monday for the Presidents Day holiday. European Union finance ministers pressured Greece to remain in an international financial rescue program after talks collapsed on Monday. U.S.-listed shares of the National Bank of Greece fell 11 percent to $1.44 in heavy premarket trading.
In eastern Ukraine, Pro-Russian separatists said they would not carry out an agreement to pull back heavy guns, putting a shaky peace deal at risk.
While the United States has little direct exposure to either Greece or Ukraine and Russia, any breakdown in either place could lead to continued volatility in Europe, a major trading partner.
While U.S. crude futures dipped 0.3 percent, slipping after a two-day rally of more than 7 percent, Brent crude was up 0.7 percent at $61.86 on expectations that lower prices may prompt a slowdown in U.S. output. Separately, bombings by Egypt against Islamic State targets in Libya raised concerns about a threat to Middle East supplies.
Crude oil remains sharply down from a high hit in June, pressuring energy stocks. On Monday, offshore drilling company Transocean Ltd slashed its dividend, and its chief executive stepped down. The stock was little changed in heavy premarket trading.
Medtronic Plc added 2.3 percent to $77 premarket. The medical device maker reported earnings growth of 28 percent, boosted by higher sales of its cardiac devices.
Corporate earnings have also supported the equity gains. Of the 391 S&P 500 companies reporting results so far this quarter, about 71.1 percent have topped profit expectations, according to Thomson Reuters data, while 57.5 percent have beaten on revenue. The earnings growth rate for the quarter is 6.6 percent, down from the 11.2 percent expected on Oct. 1, but up from 4.2 percent expected on Jan. 1.
On the downside, Celsus Therapeutics plummeted 84 percent to $1 premarket after the company's lead drug failed a mid-stage study. VBL Therapeutics Inc dropped 44 percent to $7.90 before the bell. It said it would stop developing its experimental inflammatory drug to fight ulcerative colitis and psoriasis.
Futures snapshot at 8:47:
* S&P 500 e-minis were down 4.25 points, or 0.2 percent, with 234,361 contracts changing hands.
* Nasdaq 100 e-minis were up 2.25 points, or 0.05 percent, in volume of 42,712 contracts.
* Dow e-minis were down 24 points, or 0.13 percent, with 45,179 contracts changing hands. (Editing by Lisa Von Ahn, Jeffrey Benkoe and Nick Zieminski)