Boeing Co (BA.N) said it expects airline passenger traffic to rise more than 6 percent in 2015, possibly close to 6.5 percent, above its long-range forecast of about 5 percent.

The world's largest plane maker said it still expects to book firm orders for at least 750 new airplanes this year, though it has booked only 136 net orders so far in 2015.

"We've got work to do," to hit the order target, Randy Tinseth, Boeing vice president of marketing, said in a series of briefings ahead of the Paris Airshow that starts June 15.

"We have a lot of things in the pipeline," he added, referring to potential orders. "We're on plan."

Boeing's forecast is in line with actual growth in air travel. Figures released by the International Air Traffic Association (IATA) on Thursday show worldwide passenger traffic rose 6.3 percent in the first four months of 2015 compared with the same period last year. Boeing said 2014 growth was 6 percent.

Orders and traffic growth are carefully watched by investors in Boeing and European rival Airbus (AIR.PA). The stocks of both companies have languished in recent weeks amid concern that the companies will not be able to keeping booking the record-setting orders they have in recent years.

Boeing's widely watched forecast suggests that 160 million additional passengers will fly this year, and equates to a need for 900 new aircraft, not counting replacements, Tinseth said.

Airbus and Boeing combined expect to deliver more than 1,300 new aircraft this year.

Tinseth said Boeing expects cargo traffic to rise about 5 percent, and that should help the company sell more of its 747-8 freighters. IATA said cargo traffic rose 4.3 percent in the first four months of 2015, compared with the same period of 2014.