Analysts expected a decline of about 5.4 percent for the second quarter, according to a survey by FactSet.
Besides the drop in last-minute business travel, United blamed the revenue challenges on the strong U.S. dollar and lower oil prices, which forced airlines to cut fuel surcharges on international tickets.
Parent Chicago-based United Continental Holdings Inc. said Wednesday that first-quarter net income of $313 million fell from $508 million a year ago.
Fuel spending dropped 35 percent, a savings of $646 million, as airlines continue to benefit from falling oil prices.
United saw a larger-than-expected drop in last-minute business travel during the weeks around Easter and spring break, which investors feared could be a harbinger of a broader downturn in corporate travel.