Boeing Company will open a second assembly line for its long-delayed 787 jetliner in South Carolina, expanding beyond its longtime manufacturing base in Washington state to take advantage of economic incentives and a nonunion work force.

The decision ended in interstate competition for the huge factory, with South Carolina production of a plane crucial to Boeing’s future but one plagued by problems stemming partly from the company’s reliance on suppliers spanning the globe.

About 55 airlines have ordered some 840 of the planes since the program was launched in 2003 — far more than any other Boeing plane at the same stage of development.

Boeing also has long complained about the business climate in Washington and frequent strikes by production workers. At Boeing’s plant in North Charleston, workers last month voted against continued representation by the International Association of Machinists.

Boeing has postponed the plane’s inaugural test flight and deliveries five times, putting it more than two years behind schedule. The delays have cost Boeing credibility and billions of dollars in anticipated costs and penalties.

The company could break ground in South Carolina as soon as next month, with the first 787 slated to leave the factory in the first quarter of 2012. The company aims to produce 10 of the planes a month by 2013. By comparison, it makes about 31 of its 737s and seven of its popular 777s a month.