(Adds analyst expectations, detail on costs, estimates.)
TORONTO, May 5 (Reuters) - Canada's WestJet Airlines Ltd reported better than expected first-quarter earnings on Tuesday, helped by lower fuel costs and an improvement in other operating costs.
Cost per available seat mile, a key cost measure for airlines, fell 7 percent from a year earlier. Excluding fuel and employees' profit shares, it improved 1.1 percent.
WestJet had said previously that it expected fuel costs to drop by up to 30 percent in the quarter.
Total revenue rose from a year earlier, but revenue per available seat mile eased 0.7 percent, and the airline's load factor, a measure of how effectively it is filling seats, slipped to 81.6 percent from 83.1 percent.
Ancillary revenue rose 64 percent to C$83.1 million in the quarter, boosted by new fee on first checked bags that WestJet introduced in September.
Once a no-frills domestic carrier, WestJet is increasingly going head-to-head with Air Canada, adding international routes and boosting capacity while vowing to keep fares low.
Net earnings rose to C$140.7 million ($116.4 million), or C$1.09 a share, from C$89.3 million, or 69 Canadian cents per share, a year earlier. Revenue rose 4 percent to C$1.08 billion.
Analysts, on average, had been expecting earnings of 99 Canadian cents a share on C$1.08 billion in revenue, according to Thomson Reuters I/B/E/S.
$1 = $1.21 Canadian Reporting by Allison Martell; editing by Jason Neely