Budget airline Norwegian Air Shuttle said it carried 18 percent more passengers in August than a year earlier, filling a higher proportion of available seats while adding new services.

Norwegian Air said Tuesday it carried 1,007,623 passengers last month. Total passenger traffic measured by the number of passengers and kilometers flown (RPK) rose 9 percent.

"The increase in passenger traffic, production and passengers is related to the group's expansion in established markets and to the introduction of new routes from September 2008 to August 2009, as well as adjustments in production capacity," Norwegian said in a statement.

The yield -- the average revenue per passenger carried and kilometer flown -- was estimated at 0.58 Norwegian kroner in August, down from 0.59 kroner in both July 2009 and in August of last year.

The load factor rose in August by two percentage points from a year ago to 81 percent, the airline said.

It said the average flying distance fell by 7 percent year on year.