US STOCKS-Wall St set to open lower as Greek crisis worsens
* Greece faces default on 1.6 bln euros
* Euro STOXX 50 index set for worst day since 2011
* S&P futures volume twice the average at this time of day
* Futures down: Dow 186 pts, S&P 22.50 pts, Nasdaq 56.25 pts (Adds details, comment, shares)
By Sweta Singh
June 29 (Reuters) - U.S. stock index futures fell around 1 percent in heavy trading on Monday after Greek bailout talks broke down, intensifying fears that it could be the first country to exit the euro zone.
Markets around the world fell on fears the problem could spread to other European countries. The blue-chip Euro STOXX 50 index towards its biggest one-day percentage loss since late 2011.
The European Central Bank froze funding to Greek banks, forcing Athens to shut banks for a week to keep them from collapsing.
"What the Greek government is doing is almost unprecedented for developed nations," said Adam Sarhan, chief executive of Sarhan Capital in New York. Continuación...