ATLANTA - Delta Air Lines says last month's computer outage, which caused it to cancel 2,300 flights, cost $100 million in lost revenue.

The airline also said that a key revenue-per-mile figure fell sharply in August, partly because of the outage.

Delta reported that passenger revenue for every seat flown one mile fell 9.5 percent in August compared with a year earlier. Delta attributed 2 points of the decline to the outage.

A fire and failure of a piece of equipment at Delta's Atlanta headquarters on Aug. 8 caused a massive outage of the airline's computer systems, temporarily grounding flights and leading to three days of heavy cancellations and delays.

Southwest Airlines Co. reported lost revenue and extra costs totaling $54 million from a July outage that resulted in a similar number of canceled flights.