CHICAGO, Aug 6 (Reuters) - Microsoft ( MSFT ) on Tuesday

blamed Delta Air Lines ( DAL ) for its dayslong struggle to

recover from a global cyber outage that led it to cancel more

than 6,000 flights.

In a letter from an external lawyer, the company said while

it is still investigating the circumstances surrounding the

CrowdStrike ( CRWD ) incident, its preliminary review suggests that

Delta, unlike its competitors, apparently has not modernized its

IT infrastructure.