* January load factor 77.8 pct vs year-earlier 78.8 pct
* Traffic up 9.7 percent, capacity climbs 11.2 pct
* Sees improved pricing, demand, business bookings (Adds company comments, stock price)
OTTAWA, Feb 3 (Reuters) - WestJet Airlines Ltd (WJA.TO), Canada's No. 2 carrier, said on Thursday that it boosted capacity in January, resulting in it flying slightly emptier planes than it did the year before.
WestJet said demand for air travel is rising and so are prices, allowing it to increase capacity. It said it was also encouraged by growth in business bookings.
The Calgary-based airline said its load factor, the percentage of available seats filled with paying customers, fell to 77.8 percent from 78.8 percent in January 2010 due to the higher number of seats available.
Load factor is a key industry measurement. It was the second-highest for the month of January in WestJet's history, the company said.
"Our capacity additions continue to be absorbed and we are happy with our strong January load factor," WestJet Chief Executive Gregg Saretsky said in a statement.
Traffic, or revenue passenger miles, rose 9.7 percent, while capacity, or available seat miles, increased by 11.2 percent from the year-prior period.
Shares of WestJet, which reports quarterly financial results on Feb. 9, were unchanged at C$13.28 on the Toronto Stock Exchange on Thursday morning.
$1=$0.99 Canadian Reporting by Susan Taylor, with additional reporting by Isheeta Sanghi in Bangalore; editing by Peter Galloway