CHICAGO (AP) — Boeing Co. will ramp up production of the next-generation 737, its most popular jet.

The world's second-biggest maker of commercial planes said Wednesday that it plans to build 42 of the jets per month by the first half of 2014. Then it will boost production further to an average of two of the planes per workday for a total of nearly 500 a year. It currently assembles 31.5 of the planes per month, it said.

The aerospace manufacturer already makes more 737s than any other plane, with a backlog of 2,101 orders. The company has also raised production of its 777 to seven per month from five, and plans to go to 8.3 per month in the first quarter of 2013.

New "passenger comfort" features, including greater headroom and adjustable lighting, have spurred demand for 737s to "unprecedented" levels, Boeing Commercial Airplanes President and CEO Jim Albaugh said in a statement. The increase in production should be aided by investments the company already has made in the program.

"We believe that many of the capital investments and production system changes made for 38 airplanes per month will already position us to build 42," said Beverly Wyse, vice president and general manager of the 737 program.

Boeing is the biggest maker of commercial planes after Airbus, based on 2010 deliveries. Airbus delivered 510 commercial planes last year, compared with 462 for Boeing.

Shares of Boeing rose 25 cents, or less than 1 percent, to $74.89 in morning trading.