Chicago ? Boeing is in the middle of a three-week hold on assembling pieces of its new 787.

The manufacturing delay is the latest problem for Boeing’s new plane. Flight tests stopped last month because of an electrical fire, and the first delivery officially slated for early next year is widely expected to be pushed back.

Boeing Co. spokesman Scott Lefeber said on Monday that the 16-day hold began late last month. He said Boeing is not asking the companies that make parts for the 787 to slow or stop production. Assembly work happens five days a week, so the 16-day hold adds up to a little more than three weeks.

“They will not stop production during this time. They will continue to work and will ship their assemblies according to the revised schedule,” he said.

He said Boeing would finish revising the 787 schedule in a few weeks.

Last week Spirit AeroSystems Holdings Inc. said it was shifting some workers away from the 787 to work on other planes instead. Spirit makes the front of the 787 in Wichita, Kan., and installs the electrical systems in it. The big pieces of the 787 are transported to Everett, Wash. for assembly. The company said some work would continue on the 787.

Continental Airlines was scheduled to be the first U.S. carrier with a 787, and planned to begin flights between Houston and Auckland, New Zealand, in Nov. 2011. Those are being pushed into 2012 because of “the uncertainty of Boeing’s new delivery date,” Continental spokeswoman Julie King said.

Continental was supposed to get the plane in the second half of 2011. King said Continental has not yet gotten a new delivery date from Boeing.

She also said Continental will fly a planned route between Houston and Lagos, Nigeria, with a Boeing 777 instead of the 787. Those flights are set to begin in November 2011.

Boeing shares rose 16 cents to $66.70 in afternoon trading. Shares of Continental’s parent, Chicago-based United Continental Holdings Inc., fell 78 cents, or 2.8 percent, to $26.96.

The latest delay was reported by the aerospace site Flightglobal.com.