NEW YORK (MarketWatch) -- Delta Air Lines said Monday it expects to have a "solidly profitable" second quarter as higher revenues have largely offset a jump in fuel prices. Passenger revenue per available seat mile is forecast to climb 10% in the current period, the Atlanta-based airline said. Fuel during the period was up by 91 cents from a year ago to $3.23 a gallon, though that's expected to decline in the third quarter to $3.03 a gallon. To tame its non-fuel costs and bring them down to 2010 levels, Delta said it plans to reduce its post-Labor Day seat capacity by 4% by retiring older aircraft it will no longer have to service and reduce its workforce. Delta expects to end the second quarter with $5.6 billion in unrestricted liquidity.