Delta Air Lines said that its ticket sales had stabilized and started to improve, putting it on course to deliver third-quarter revenue within its original forecast range. “For Delta, they bottomed out in the later part of August and the first part of September,” Chief Executive Ed Bastian told reporters on Sunday on the sidelines of a meeting of airlines group IATA. “Business traffic is growing back in the U.S.” In July, the company had forecast a 30%-35% drop in third-quarter adjusted revenue versus 2019 levels. Last month, the airline said quarterly revenue would be at the lower end of the forecast after a resurgence in COVID-19. A Delta official on Monday said there has been no update to the outlook the company provided last month. The airline is due to report results for the quarter through September on Oct. 13. Bastian said domestic travel bookings are expected to surpass 2019 levels next year. Later, the airline said it would boost its capacity at Boston by more than 20% next summer over the 2019 peak, by adding five new routes including two international destinations.