US STOCKS-Wall St set to open lower on Ukraine worry, deal failures
* Russia has 20,000 troops on Ukraine border -NATO
* Sprint, T-Mobile shares fall as Sprint drops bid
* Cognizant, Groupon shares down after results
* Futures off: Dow 63 pts, S&P 8 pts, Nasdaq 25 pts (Updates prices, adds byline)
By Rodrigo Campos
NEW YORK, Aug 6 (Reuters) - U.S. stocks were poised to fall at the open Wednesday on worries of an escalation of the conflict in Ukraine and after several key merger and acquisition deals fell through.
* NATO said Wednesday Russia has amassed around 20,000 combat-ready troops on Ukraine's eastern border and could use the pretext of a humanitarian or peace-keeping mission to invade.
* A further souring of relations between Russia and the West could hurt the European economy, already struggling to recover from a deep recession. Data on Wednesday showed German industrial orders dropped in June at their steepest rate since September 2011 and Italy's economy unexpectedly slid back into recession in the second quarter.
* Sprint dropped its bid for carrier T-Mobile U.S. after continued regulatory resistance despite months of lobbying. Sprint shares fell 17.5 percent and T-Mobile dropped 8.6 percent in heavy trading before the opening bell. Continuación...