The Asian firm is described as a "leading polysilicon manufacturer".
GT Solar will provide the anonymous company with new chemical vapour deposition (CVD) equipment and related polysilicon production services.
Further details of the deal were not disclosed.
US firm GT Solar, based in Merrimack, New Hampshire, is a global provider of specialised equipment and technology for the solar industry.
Chief executive Tom Gutierrez says: "The polysilicon market is ultimately a commodity market that will eventually be dominated by large, low-cost players.
"As
