Delta Air Lines this week reaffirmed its intention to place Embraer regional jets with its mainline operation by entering a deal with Boeing that includes orders for 20 used E190s and 20 new Boeing 737-900ERs. The deal, announced on December 16, follows the cancellation of an agreement earlier this year between Delta and Boeing that would have covered the same 20 former Air Canada E190s along with 40 of the 737s. At the time, the U.S. carrier said it canceled the orders because it could not reach an agreement with the Air Line Pilots Association on a new contract that would have included a pay scale for mainline E190 operations. However, according to Delta, the orders announced Wednesday offered “more compelling economics” than the previously announced order. The airline continues negotiations with its pilots over a new labor contract.

“Delta continues to look for opportunities to deploy larger aircraft, which bring customer experience enhancements and improved economics, across its fleet,” said Greg May, Delta’s senior vice president for supply chain management. “This aircraft order is another example of Delta’s unique fleet strategy to deploy a mix of new and used aircraft, maintain low capital costs, and leverage significant capacity flexibility to produce superior returns for our shareholders.”

Plans call for the E190s, owned by Boeing Capital Corp., to enter revenue service in early 2017. The airplanes would come with what Delta calls a unique cabin design that includes two-by-two seating in the main cabin and a one-by-two configuration in first class.

The additional Boeing 737-900ERs will bring the total in Delta’s fleet to 120 by 2019, the airline said. In 2011 Delta placed a firm order for 100 Boeing 737-900ERs, 50 of which have so far entered service.