U.S. futures slip as Greece continues to weigh

* The International Monetary Fund dramatically raised the stakes in Greece's stalled debt talks late on Thursday, announcing that its delegation had left negotiations in Brussels and flown home because of "major differences" with Athens. * The University of Michigan's preliminary June reading on the overall index on consumer sentiment is expected to have risen to 91.5 from 90.7.

U.S. futures slip as Greece continues to weigh source: http://finance.yahoo.com/news/u-futures-slip-greece-continues-114137815.html