Toray Industries Inc. is set to seal a ¥1 trillion deal to supply carbon fiber for Boeing Co. jets and will spend around ¥100 billion to build a new U.S. plant to produce the material, sources said Monday.

Toray will supply carbon fiber composites for Boeing's flagship 787 Dreamliner as well as its next-generation 777X large commercial plane for more than 10 years, the sources said. The chemical product maker was to hold a news conference later Monday to announce the agreement.

The deal is expected to solidify Toray's leading position in the global carbon fiber market, following its current supply contract with Boeing that runs from 2006 to 2021.

To meet the new capacity requirements, Toray will build a plant on a 1.6 million-sq.-meter site in South Carolina, with operations to begin possibly in 2017, according to the sources. The company currently operates four carbon fiber-producing plants, in Japan, France, South Korea and Alabama in the U.S.

Carbon fiber, 75 percent lighter but more than 10 times stronger than iron, is used in a broad range of products, including autos and shale gas containers.