Canada's major airlines reported record load factors last year, with planes carrying substantially more passengers on average than than ever before.

Montreal-based Air Canada says its monthly load factor hit 82.1 in December and was 82.7 per cent for 2012 as a whole.

Each figure rose by 1.1 percentage points, and the annual figure represents an all-time record for Canada's biggest airline.

Load factor is a closely watched industry metric that tracks the percentage of passengers in available seats on any given airline's flights.

Air Canada expanded its seat capacity by 1.8 per cent in 2012, so there were more seats available overall. But passenger traffic increased by even more, 3.2 per cent in December, which caused the load factor to jump.

The airline booked 12.6 billion revenue passenger miles in 2012 as a whole.

WestJet also hits record

Meanwhile, Air Canada's main rival, WestJet, saw its load factor increase. For the year as a whole, Calgary-based WestJet's passenger traffic was up 7.1 per cent to 4.5 billion revenue passenger miles.

WestJet's December load factor was 81.9 per cent, up one point from a year earlier. Its full-year load factor was also 81.9 per cent, up 3.2 points from 2011.

"We are very pleased to close out the year with six consecutive monthly load factor records and record high loads in all four quarters," CEO Gregg Saretsky said.

And Porter Airlines, says it carried 2.45 million passengers in 2012, a 15 per cent increase over the 2011 level.

Toronto-based Porter said its load factor for 2012 as a whole increased to 62 per cent from 61.7 per cent.

December alone saw a 3.5 per cent increase in revenue passenger miles to 77.8 million, and the load factor for the month was 64.3 per cent.

With files from The Canadian Press