Stock futures drop on Fed's discount rate hike

U.S. stock index futures dropped late on Thursday after the Federal Reserve raised the discount rate that it charges banks for emergency loans.

* S&P 500 futures fell 7.20 points, while Nasdaq futures lost 10.8 points, and Dow futures slid 51 points.

* The Fed, citing improvement in financial market conditions, said the discount rate would be increased to 0.75 percent from 0.50 percent, effective Friday.

* The Fed's move marked a possible drawing down of the liquidity that has propelled markets as the Fed pushed ahead with efforts to revive the economy.

(Reporting by Ellis Mnyandu; Editing by Kenneth Barry)