Chinese chipmaker Yangtze Memory Technologies Co (YMTC) has filed a lawsuit against U.S. rival Micron Technology alleging infringement of eight of its patents.

YMTC filed the lawsuit against Micron and unit Micron Consumer Products Group on Nov. 9 at the U.S. District Court for the Northern District of California.

According to the lawsuit, Micron turned to YMTC's patented technology to fend off competition from YMTC and to gain and protect market share. It said Micron was not paying its fair share to use the patented inventions.

YMTC did not respond to a request for comment. Micron did not respond outside regular U.S. business hours.

Micron makes DRAM chips and NAND flash memory chips and competes with South Korea's Samsung Electronics and SK Hynix as well as Japan's Kioxia, a unit of Toshiba. YMTC is a much smaller rival which was last year barred by the U.S. from buying certain American components.

The U.S. in recent years has increased restrictions on exporting chipmaking technology to China on security grounds.

In May, China said Micron products failed a network security review and barred purchase of them by operators of key infrastructure.

Micron was embroiled in a dispute in 2018 involving Chinese state-backed chipmaker Fujian Jinhua which was accused of - and which denied - trade secret theft. Later that year, its main products were subject to a temporary sales ban in China.

China was once Micron's biggest market, generating half of its $20 billion revenue in fiscal 2017. That share shrank to 16% in 2022, a year in which it closed DRAM operations in Shanghai.

Micron has said it remains committed to China. In June, it said it would invest 4.3 billion yuan ($590 million) in coming years in its chip-packaging plant in Xian city, and it exhibited for the first time at a trade expo in Shanghai this month.

($1 = 7.2934 Chinese yuan renminbi)

(Reporting by Anirudh Saligrama and Brenda Goh; Editing by Christopher Cushing)