POCATELLO, Idaho (AP) ¿ Hoku Scientific Inc., the maker of solar products, and Solarfun Power Holdings Co. Ltd., a solar cell manufacturer, on Tuesday said the companies agreed to amend the prepayment and shipping schedules of their supply agreement. The agreement, made between Hoku subsidiary Hoku Materials Inc. and Solarfun subsidiary Solarfun Power Hong Kong Ltd., originally obligated Solarfun to pay Hoku $18 million by March 31, 2009, and an additional $5 million by March 31, 2010, as a prepayment for polysilicon products. The amendment spreads the $18 million payment in installments from March to October 2009 and reschedules the $5 million payment for January 2010. In exchange, Solarfun has agreed to extend the date when Hoku is obligated to begin shipments of polysilicon from September 2009 until March 2010. Solarfun has the right to terminate the amended supply agreement if Hoku has not started shipments by June 30, 2010, and Hoku has the right to terminate the agreement, and retain all prepayments received, if Solarfun fails to pay any of its future prepayments when due. Shares of Hoku jumped 18 cents, or 7.4 percent, to $2.63. Solarfun shares climbed 58 cents, or 14 percent, to $4.61.