* Futures: Dow down 34 pts, S&P 3 pts, Nasdaq off 27 pts
By Sruthi Shankar
March 21 (Reuters) - U.S. stock index futures were lower on Wednesday as traders moved cautiously ahead of an expected Federal Reserve interest rate hike and continuing fallout from Facebook Inc's data privacy breach.
The Fed is widely seen raising its benchmark interest rate by 25 basis points when it concludes the first meeting of the Jerome Powell era at 2:00 p.m. ET.
An increase would mark its sixth hike since late 2015 when the U.S. central bank started gradually tightening monetary policy following a period of near-zero interest rates in the aftermath of financial crisis in 2008. It would be the first since Powell succeeded Janet Yellen as Fed chair in February.
While markets are sure about the quarter-point hike, they are less confident of what the Fed signals next: three hikes this year as previously forecast by policy makers or four. Some investors believe that corporate tax cuts and recent hints of inflation pressures will push policymakers to add an additional increase beyond the expected three.
One worry among equity investors is faster rate hikes could dent the appeal of stocks relative to bonds as fixed income securities become less pricey than they've been in the low-rate era. Stocks, meanwhile, remain relatively expensive despite recent pull backs.
Ahead of the Fed announcement, 2-year Treasury note yields , which are highly sensitive to Fed policy expectations, hit their highest in more than nine years on Wednesday morning at 2.35 percent.
Aside from the Fed, tech shares looked under pressure again as Facebook's data privacy travails persisted. Its shares were down 1.5 percent in premarket trading, on track for its third day of losses amid uproar over the alleged misuse of users' data.
Facebook shares have lost about 9 percent in just two days, and hurt shares of other social media companies such as Twitter and Snap Inc as the issue raised broader questions about consumer privacy and whether tougher regulation is on the horizon.
By 6:56 a.m. ET, Nasdaq 100 e-minis were down 27 points. Dow e-minis were off by 34 points, and S&P 500 e-minis were 3 points lower.
Investors were also uneasy about Washington's ability to meet a Friday deadline to avert a government shutdown and by the Trump administration's threats to impose import duties on China. (Reporting by Sruthi Shankar in Bengaluru Editing by Dan Burns)