US STOCKS-Futures flat after two-day gain; Staples, Home Depot fall
* Staples, Home Depot fall after earnings
* More AstraZeneca investors disprove of Pfizer rejection
* Aeroflex jumps, to be acquired by Cobham for $1.46 bln
* Futures up: Dow 10 pts, S&P 0.75 pt, Nasdaq 4.25 pts
By Chuck Mikolajczak
NEW YORK, May 20 (Reuters) - U.S. stock index futures were little changed on Tuesday, after the S&P 500 advanced for two straight days and investors assessed some of the final corporate results of earnings season.
* Home Depot lost 1.6 percent to $75.25 in premarket trade after the home improvement retailer reported lower-than-expected quarterly sales as its spring selling season got off to a slow start.
* Staples Inc tumbled 10.6 percent to $11.97 after the office supply retailer posted first-quarter earnings and forecast a decline in sales in the current quarter.