Four Japanese chip makers have shied away from filing an antidumping petition against South Korean rivals that, the domestic makers say, export dynamic random access memory chips to Japan at unfairly low prices, according to industry sources.

The four will not file a request with the Japanese government to impose antidumping tariffs on DRAMs from South Korea, as they apparently lag behind their South Korean and U.S. rivals in competitiveness in the global DRAM market, the sources said Thursday.

The four are NEC Corp., Toshiba Corp., Mitsubishi Electric Corp. and Hitachi Ltd.