* S&P 500 down for four of the past five sessions
* Apple seen unveiling new iPhone next month
* Tesla Motors falls in premarket after downgrade
* Futures down: Dow 50 pts, S&P 8.5 pts, Nasdaq 14.5 pts
By Ryan Vlastelica
NEW YORK, Aug 12 U.S. stock index futures were lower on Monday, indicating the previous week's decline would continue as investors found few reasons to buy.
* The S&P 500 has fallen in four of the past five sessions, receding from record levels as uncertainty over the timing to the end of the Federal Reserve's stimulus policy has weighed on sentiment. Also, mixed economic data and the winding down of the earnings season have offered few catalysts to equities.
* Recently several Fed officials have indicated the central bank will likely cut back on its program next month as long as economic growth meets its forecasts. Many investors are concerned the economy will stall without the Fed's intervention.
* Chinese shares rose to a two-month high as the South China Morning Post reported that authorities in Beijing were offering stimulus to key cities and provinces to bolster a slowing economy.
* S&P 500 futures fell 8.5 points and were below 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 lost 50 points, and Nasdaq 100 futures slid 14.5 points.
* Shares of Apple Inc will be in focus after technology blog AllThingsD reported the company was expected to present a redesigned iPhone in September. Shares added 0.3 percent to $455.99 in light premarket action.
* Rockwell Collins Inc agreed to buy Arinc Inc, an aerospace communications firm, for $1.39 billion from Carlyle Group LP.
* Tesla Motors Inc dipped 1.3 percent to $151 premarket after Lazard downgraded the stock to "neutral" from "buy."
* Earnings season is winding down, with 446 companies in the S&P 500 having reported. Of those, 68 percent have exceeded analysts' expectations, slightly above the 67 percent beat rate over the past four quarters, Thomson Reuters data showed.
* Sysco Corp is the only S&P 500 company scheduled to report quarterly results on Monday. There are no major economic indicators on tap.
* U.S. stocks fell on Friday, posting their biggest weekly decline since June, as investors focused on the timing of the Federal Reserve action.