Shares of Hoku Scientific Inc. rose sharply yesterday after the company announced that it will provide up to $678 million in polysilicon to Suntech Power Holdings Co. over 10 years.

Shares of Hoku jumped $3.32, or 72 percent to $7.90 in after-hours trading on the Nasdaq Stock Market.

Hoku Materials, an Idaho-based Hoku subsidiary, will begin providing the material to Suntech in mid-2009.

"We are pleased to have established this relationship with Suntech, a long-term leader in the solar industry," said Dustin Shindo, chief executive for Hoku Scientific. "Their rapid growth and dynamic leadership team make them an ideal partner for our company."

Hoku is in the process of building a plant in Pocatello, Idaho, capable of producing 2,000 metric tons of polysilicon per year. Hoku announced in January that it signed a seven-year $370 million polysilicon supply contract with Sanyo Electric Co. Polysilicon has been in great demand recently because of its use in making solar power cells and computer chips.

Kapolei-based Hoku estimates that total plant construction costs could reach $260 million.

The newly announced contract also provides for an initial deposit of $2 million to Hoku upon signing and requires that Suntech make additional prepayments for products in the amount of $45 million. The contract includes a provision that allows for either party to cancel years 8 through 10 of delivery for any reason.

Shares of Hoku have see-sawed between $2 and $8 a share during the last year. The company's stock was initially sold to the public for $6 a share in August of 2005.

Reach Sean Hao at shao@honoluluadvertiser.com.