AMSC’s move stems back to April when its largest customer, Sinovel, refused to accept a shipment of wind turbine components.
In statement AMSC said it believed Sinovel had "believes that Sinovel illegally obtained and used AMSC’s intellectual property to upgrade its 1.5 megawatt wind turbines in the field to meet proposed Chinese grid codes and to potentially allow for the use of core electrical components from other manufacturers".
AMSC also said it has filed a claim for arbitration to compel Sinovel to pay AMSC for the contracted shipments that were refused.
It said: "This has been filed with the Beijing Arbitration Commission in accordance with the terms of AMSC’s supply contract with Sinovel."
At the time it was revealed Sinovel had refused the components, the company denied any wrongdoing and described its action as a normal adjustment of production and management.
In 2008 and 2010, AMSC and Sinovel signed two component supply contracts to the value of nearly $900 million.
Sinovel was unable to comment.