United Continental is exploring options to replace more than 90 Boeing 757 mid-size, narrow-body twin-engine jet airliners, reports Aerospace-Technology.com. Production of the Boeing 757 ended in 2004.

Airbus A321LR. Source: Airbus United Continental Fleet vice president Ron Baur was quoted by the Wall Street Journal as saying that the company was considering both the Airbus Group's under-development A321LR single-aisle jetliner and an all-new jet being drafted by Boeing.

Baur is quoted as saying, "When we look at the A321LR, it looks like a pretty decent airplane, but since we have the luxury of time in terms of waiting to see what Boeing's going to do in the middle-of-the-market airplane, we're in no rush to make a decision on that."

Evaluations are believed to be at the conceptual stage as the airline's 757 fleet is comparatively young. The airline offers regular flights with the aircraft on extended routes across the Atlantic, which do not require a larger twin-aisle jetliner.

The Airbus A321LR is the upgraded version of the A321neo and features new fuel tanks and the ability to carry an additional four metric tons of passengers and cargo.

While A321LR is scheduled to be available in 2019, the launch date for Boeing's concept model remains unknown.