NEW YORK, Aug 5 (Reuters) - S&P 500 stock index futures briefly turned negative on Wednesday following a report that showed U.S. employers cut far more private-sector jobs than expected in July.
* The ADP employment data came two days before the release of the government's all-important non-farm payrolls report for July.
* S&P 500 futures shed 1.90 points and were near 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 rose 5 points, and Nasdaq 100 futures slipped 2.5 points.