boeing actively marketed the 717 to a number of large airlines, including northwest airlines, who already operated a large fleet of dc-9 aircraft, and lufthansa. boeing also studied a stretched, higher-capacity version of the 717, to have been called 717-300, but decided against proceeding with the new model, fearing that it would encroach on the company's 737-700 model. production of the original 717 continued. boeing continued to believe that the 100-passenger market would be lucrative enough to support both the 717 and the 737-600, the smallest of the next-generation 737 series. while the aircraft were similar in overall size, the 737-600 was better suited to long-distance routes, while the lighter 717 was more efficient on shorter, regional routes.