* WestJet May load factor 79.2 pct vs May 2011's 74.8 pct
* WestJet CEO says summer bookings look strong
* Porter Airlines May load factor 60.5 pct vs 59.5 pct previously
* Air Canada data expected later on Tuesday (Recasts with analyst comment, CEO quotes)
June 5 (Reuters) - WestJet Airlines said on Tuesday that reservations for the approaching summer months looked strong as Canada's second-biggest carrier r eported that it flew fuller planes in May than a year earlier.
WestJet said its load factor - the percentage of available seats filled with paying customers - rose to 79.2 percent from 74.8 percent in May 2011 as a 7.2 percent increase in traffic dwarfed a capacity increase of 1.3 percent.
Forward bookings are "showing continued strength as we head into the busy summer flying season," WestJet Chief Executive Gregg Saretsky said in a statement.
National Bank Financial analyst Cameron Doerksen said the May data puts WestJet on pace to beat his second-quarter load factor estimate of 78 percent.
"We expect June's traffic results to benefit from new routes, in particular between Toronto and New York (LaGuardia)..," Doerksen said in a note to clients.
Low-cost airline WestJet on Monday launched seven daily non-stop flights between Toronto and New York's LaGuardia airport as it continues to muscle in on the business travel market in an attempt to boost revenue and profits.
WestJet stock rose 2.5 percent to C$15.38 on the Toronto Stock Exchange on Tuesday morning. Other North American airlines stocks were also higher.
Separately, privately owned regional airline Porter said its load factor rose to 60.5 percent in May from 59.5 percent in the same month last year. Tr affic on the carrier, up 14.4 percent in May, outstripped a capacity increase of 12.5 percent.
Air Canada's monthly data is expected later in the day. (Reporting by Nicole Mordant in Vancouver and Shounak Dasgupta in Bangalore; Editing by Janet Guttsman)