Companies around the world hit by Microsoft outage

One of the biggest-ever IT outages has disrupted companies across the world, from airlines to financial services and media groups, after what should have been a routine software update cascaded into crisis.

Thousands of flights were cancelled on Friday, workers in cities from Tokyo to London were unable to log on to their computers, hospital operations were postponed and some television channels went off air.

The outage has been blamed on a…