Delta Air Lines Inc.’s second-quarter profit beat analyst expectations as cheap fuel overcame foreign-currency weakness against the dollar and a nagging decline in fares. Adjusted earnings were $1.47 a share, topping the $1.42 average of 13 analyst estimates compiled by Bloomberg. Revenue was $10.4 billion, compared with the average estimate of $10.5 billion. The carrier said it expects unit revenue, or passenger revenue for each seat flown a mile, to fall by 4 percent to 6 percent in the current quarter. The carrier also said it would cut planned capacity growth, expanding available seats by 1 percent in the fourth quarter instead of the previously planned 2 percent, responding to investor concerns that too much capacity was weighing on fares. The Atlanta-based carrier said it was planning deeper capacity reductions on routes to the U.K. due to the recent drop in the pound and economic uncertainty after the country voted to leave the European Union. “While the revenue environment remains challenging, with persistent headwinds from close-in domestic yields and geopolitical uncertainty, we remain focused on achieving our goal of positive unit revenues by year end,” Glen Hauenstein, Delta’s president, said in the statement.