* S&P 500 has struggled to close over 100-day moving average
* Energy to be in focus with Syria situation uncertain
* H&R Block posts wider-than-expected quarterly loss
* Dow down 11 pts, S&P up 0.1 pt, Nasdaq down 2 pts
By Ryan Vlastelica
NEW YORK, Sept 4 (Reuters) - U.S. stock index futures were little changed Wednesday as a Western military strike against Syria appeared more likely, though a decision over it remained several days away.
The odds for military action had appeared to ebb over the weekend after U.S. President Barack Obama said he would seek Congressional authorization for a strike. While Congress won't vote until it returns from its summer recess on Sept. 9, key congressional figures back the plan, suggesting approval may be more likely.
Secretary of State John Kerry said any resolution approving military force would prohibit "boots on the ground," suggesting that a strike would be limited in scope.
"I think a relatively minor strike is now built into the market. If the scope changes and we start talking about regime change, the market will have to adjust again to that," said John Brady, managing director at R.J. O'Brien & Associates in Chicago.
"Until we get more clarity on the geopolitical news, I suspect we'll continue trading in a tight range."
Uncertainty over Syria has been the market's primary driver over the past week, with investors concerned about the economic impact of any action. Energy has been the most impacted, with crude rising 1.6 percent over the past two weeks as investors bet that a Middle East engagement would limit oil supplies.
Adding to concern overseas, Italian shares slumped on worries over the survival of the country's government. European shares lost 0.4 percent.
S&P 500 futures rose 0.1 point and were slightly above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures slid 11 points and Nasdaq 100 futures lost 2 points.
On the S&P 500, investors will be watching the 1,639.88 level, the index's 100-day moving average. The index has risen above that level in each of the past four sessions, though it hasn't closed above it since Aug. 26, a sign that near-term momentum continues to stall.
H&R Block Inc reported an adjusted quarterly loss late Tuesday that was wider than expected, citing higher costs. Shares fell 4.9 percent to $26.50 in premarket trading.
SAIC Inc and Dollar General Corp reported results early on Wednesday.
Hain Celestial Group Inc shares will be in focus a day after the company said that activist investor Carl Icahn and his entities were cutting their stake in the company by roughly half.
While geopolitical issues have been the primary focus for investors, they also await the latest economic data, with the July international trade figures out at 8:30 a.m. EDT (1230 GMT).
The U.S. Federal Reserve's Beige Book summary of economic conditions will be released at 2:00 p.m., and the report will be closely scoured for insight into when the central bank may begin to slow its accommodative monetary policies, which have fueled the equity market's gains in 2013.
Wall Street rose on Tuesday, but pared its gains in afternoon trading as key figures in Congress announced support for military action against Syria.