DALLAS » Southwest Airlines Co. added an upbeat note to a strong quarter for the airline industry by reporting a $112 million profit for spring and early summer.

The nation’s biggest discount airline also said yesterday that it sees no evidence travel demand is weakening, despite persistently high unemployment and consumer jitters about the economy.

Southwest said its adjusted earnings were 29 cents per share in the second quarter, enough to beat analysts’ expectations. Revenue rose 21 percent thanks to a 15 percent increase in average fares during the start of the summer vacation period.

The Dallas-based airline said business travel has strengthened but not fully recovered from pre-recession levels. But its core customer—the leisure traveler—has been packing planes.

July traffic "looks really good," and Southwest could set a company record for the percentage of seats filled this month, said CEO Gary C. Kelly.

Southwest’s net income equaled 15 cents per share, compared with $91 million, or 12 cents per share, a year earlier. The gain was 29 cents per share after excluding what Southwest called "special items." Revenue climbed to $3.17 billion.