Boeing Co. spokesperson Doug Alder would not say whether Washington state is one of those sites.
Officials in Alabama, California, Missouri, South Carolina, Texas and Utah are among those who have talked about trying to lure Boeing. Production of the plane will likely mean thousands of long-term jobs for whichever location Boeing selects.
U.S. Senator Richard Shelby, R-Ala., said that Alabama is one of the sites under consideration. "We are pleased to hear reports that Huntsville (Ala.) is in contention as a location for this expansion," he wrote in an open letter.
The sites have been asked to return their proposals by mid-December so Boeing can review them and make their final decision by early next year, Alder said.
He said the sites can come back with proposals for the final assembly of the airplane, fabrication and assembly of its composite wing, paint or all of the plane.
Asked if Washington state is one of the sites contacted, Alder said the company is "not disclosing or discussing the locations."
Boeing earlier said it would build the plane in Washington state if the Machinists Union agreed to an 8-year labor contract extension proposed by the company. Union members rejected the proposal, and Boeing officials said it would look for alternative manufacturing sites outside the Puget Sound region.
Alder said Saturday that Boeing has no plans to reopen contract talks with the Machinists Union.
If orders announced at last weekend's Dubai Air Show are any indication, the 777X is already a wild success.
"Response has been quite frankly overwhelming," McNerney said as the show came to a close. "We have secured launch commitments for 259 airplanes from four of the world's most highly respected airlines."
The orders worth nearly $100 billion came from Qatar Air, Emirates Airline, Etihad Airways, and Lufthansa.
The orders make the 777X pre-sale "the largest product launch in commercial jetliner history," McNerney said.