UPDATE 1-Air Canada planes fly fuller, WestJet's slightly emptier
* Air Canada load factor up at 83.5 pct vs 81.5 pct year ago
* WestJet load factor 86.1 pct vs 86.2 pct last year
* Porter load factor 58.1 pct vs 59.8 pct
April 3 (Reuters) - Air Canada, Canada's biggest airlines, said passenger levels for March remained strong compared to a year earlier, while the country's No. 2 carrier, WestJet Airlines, reported a fall in its numbers.
Air Canada said its load factor, or the percentage of available seats filled with paying customers, rose to 83.5 percent in March from 81.5 percent a year earlier.
Traffic increased faster, by 3.4 percent, as the capacity, or available seat miles, rose 1.0 percent.
The company reported increased traffic in the domestic, the Pacific and the U.S. trans-border markets.
Calgary-based WestJet Airlines said its load factor, or the percentage of available seats filled with paying customers, fell 0.1 percentage points to 86.1 percent.
Traffic for Calgary-based WestJet increased 8.2 percent, while capacity, measured in available seat miles, rose 8.4 percent from March 2012. Continued...