The new plane, known as the 737 MAX 10X, would offer more range to Boeing's current fleet of single-aisle jets, rivalling the Airbus A321neo, which will carry up to 240 passengers.
Such planes are popular with budget airlines that comprise a key market for both aircraft manufacturers. They are built for cross-country routes, such as New York to Los Angeles.
"Boeing is actively engaged in discussions with customers about the 737 MAX 10X," Boeing's Randy Tinseth said in a company blog post. "In fact, we?ve already extended business offers to some of those customers."
The new Boeing plane is expected to enter service in 2020, said Tinseth, vice president of marketing for Boeing's commercial division.
That would make it one year after the Airbus plane, which has racked up numerous orders since it was unveiled in late 2014.
Tinseth, who described the development plan at an industry event in California, called the build out a "relatively minor development" program.