US STOCKS-Futures flat as Greece clarity sought; S&P at record
* S&P 500 coming off first close above 2,100
* Investors looking to Fed minutes for hints of rate timing
* Exxon down in premarket, Berkshire drops investment
* Dow up 2 pts, S&P down 1.5 pt, Nasdaq up 1.25 pt
By Ryan Vlastelica
NEW YORK, Feb 18 (Reuters) - U.S. stock index futures were flat on Wednesday, a day after the S&P 500 ended above 2,100 for the first time ever, as investors waited to see whether a debt deal would be reached with Greece.
* Wall Street stocks have been tied to signs of progress or difficulty with Greece's bailout program of late, even though the United States has little direct exposure to the country. Market participants are concerned that if a deal isn't reached by Feb. 28, when a bailout program for Greece expires, that could lead to higher volatility throughout the euro zone.
* European shares were sharply higher on the day, hitting a seven-year high after the Greek government confirmed it would ask for an extension to its loan agreement. Shares in Greek banks rose 8.2 percent.
* Despite that, the situation in Greece remains uncertain, with the government in Athens also looking to renegotiate Greece's debts. Some caution lingered in the United States, where the U.S.-listed shares of the National Bank of Greece fell 7.4 percent in premarket trading. Continuación...