STMicrolectronics NV has filed a complaint in the Northern District of California alleging that InvenSense Inc., a supplier of motion tracking components based on MEMS technology, infringes nine ST patents, InvenSense said Thursday.

InvenSense (Sunnyvale, Calif.) provided a legal update and stated that it contests ST’s claims and intends to defend itself. The company said it is fully committed to its entire product portfolio, and all its products continue to be available to customers.

ST (Geneva, Switzerland) is a leading supplier of MEMS components with approximately $900 million in annual sales of MEMS components and MEM foundry services. STMicroelectronics was the leading producer of both MEMS gyroscopes and MEMS accelerometers in 2011, according to IHS-iSuppli (El Segundo, Calif.).

The market research firm asserts that ST is the sole supplier of gyroscopes and accelerometers for the iPhone and iPad and Apple accounted for half of ST’s MEMS business in 2011.