Wichita ? Boeing’s new 787 jetliner will be between 4,000 to 5,000 pounds lighter, after some redesigning to decrease the plane’s weight by 2 percent.

Company officials said Monday that a few partners in the 787 program are behind schedule, but they expect the jetliner to be delivered to customers on time.

Boeing could hire mechanics to bring some of the work temporarily in-house, but that hasn’t been necessary yet, said Mike Bair, vice president and general manager of Boeing’s 787 program.

The plane’s weight needs to be reduced because parts such as brackets and wing ribs were overdesigned, he said.

“We know where it’s at, and we just need some additional resources to do what is essentially some redesign of parts of the airplane,” he said.

Boeing officials said last month that research and development of the 787 had cost much more than expected. Despite the problems, Bair said, the aircraft will be delivered to customers as scheduled.

Spirit AeroSystems in Wichita, which is building the 787’s forward section, is on schedule, Bair said.

The nose section for the 787 is about 20 feet longer than any other nose section the company builds for other Boeing aircraft, Bair said.

Bair said the program is moving from design to the production phase, with sites where the plane will be produced working to become ready.

The 787 is scheduled to enter service in May 2008. Boeing has 455 orders from 36 customers.

The plane is sold out until 2013, making it the most successful launch of a new jetliner program, Bair said.

The company plans to increase 787 production to meet the demand, building about 112 planes in 2008 and in 2009.