UPDATE 1-United Airlines extends cancellations of Boeing 737 MAX flights through Aug. 3

United Airlines said on Friday it is extending by one month its cancellations of Boeing Co 737 MAX flights, now through Aug. 3, leading to about 40 or 45 daily canceled flights. It did not give a reason for the extension, but the August target date brings the airline more in line with rivals Southwest Airlines Co and American Airlines Group Inc , which have canceled 737 MAX flights through Aug. 5 and Aug. 19, respectively. Boeing's top-selling 737 MAX aircraft has been grounded since March in the wake of two deadly crashes that killed a combined 346 people.