China's JA Solar said today it terminated its three year contract to get solar cells from California-based SunPower, citing problems with quality and pricing.

The contract, which started on Jan. 12, was for up to 120 megawatts of silicon solar cells beginning this year.

In a statement, JA Solar said "the parties have determined that an unanticipated quality problem with respect to metallurgical grade polysilicon could not be resolved in the near term."

JA Solar also said the contract only provided pricing terms through June, but that the companies have not been able to reach a further agreement on costs.

Separately, JA Solar said it extended its wafer supply agreement with China's ReneSola. Under the contract, ReneSola will supply an additional 60 MW of wafers to JA Solar from 2008 to 2010.

"This latest agreement is in line with our growth plans and continued efforts to meet customer demand. The agreement builds on our existing relationship with ReneSola, and further strengthens our supply chain," said Samuel Yang, CEO of JA Solar.

Earlier this week, JA Solar signed a deal with Shunda Semiconductor for the supply of $46.4 million worth of silicon wafers (see China's JA Solar, Shunda in wafer supply deal).

The company said it does not expect the termination of its contract with SunPower to have a material impact on its 2007 or 2008 revenue or earnings.