Skies Turn More Surly for United Airlines.

Aug. 9--Lately, United Airlines, the leading airline serving San Francisco International Airport, has been sending more tempers flying than planes, as travelers fume over continuing flight cancellations by the world's largest air carrier.

United has canceled more than 1,000 flights since Saturday, including 226 Tuesday, blaming bad weather, busy air traffic and a labor dispute with its pilots. The Chicago-based airline is warning that more cancellations are likely before the Labor Day holiday.

United operates more than 500 flights a day from the San Francisco airport, making it by far the dominant carrier there. Although the airline also flies to San Jose and Oakland, those airports are more heavily served by other carriers.

United has publicly apologized to its passengers for inconveniencing them. But that doesn't mean much to travelers like Anne Burch, a Singapore-based financial controller for Lucent Technologies Inc. …