Hoku Scientific Inc. said its subsidiary building a polysilicon plant in Idaho has entered a contract to purchase about $6.5 million of silicon metal next year from Polymet Alloys Inc.

The three-year agreement calls for Hoku Solar Inc. to buy specified volumes of the material, though the amount may be increased. The pricing is fixed in 2009 and is to be renegotiated for the second and third years of the contract. If Hoku and Polymet are unable to agree on a price then either one of them may terminate the agreement. Hoku will use the silicon for the manufacture of tricholorsilane, a key material used in production of solar-grade polysilicon.