(REUTERS) -- Stock index futures pared losses on Thursday after a report from Automatic Data Processing showed private sector employment increased more than expected in December.

S&P 500 futures were off 4.20 points and below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration of the contract. Dow Jones industrial average futures lost 55 points, and Nasdaq 100 futures fell 9.25 points.

(Reporting By Chuck Mikolajczak; editing by Jeffrey Benkoe)