KEY TAKEAWAYSIBM shares are dropping 5% in premarket trading Thursday, weighing on Dow Jones Industrial Average futures, after its quarterly revenue fell short of Wall Street estimates.The company reported third-quarter revenue of $14.97 billion, lower than the $15.07 billion consensus estimate of analysts polled by Visible Alpha, as infrastructure revenue fell 7% and consulting revenue remained flat.IBM CEO Arvind Krishna said the group expects fourth-quarter revenue growth, in constant-currency terms, to ...