Denso Corp., Toyota Motor Corp.'s biggest auto parts supplier, said the strong yen is undermining its recovery from the March 11 earthquake and may prevent the company from raising its full-year profit forecast.

Denso raised its half-year net income forecast on Aug. 1 to ¥9 billion from ¥1 billion on a faster than expected recovery and cost-cutting efforts, while leaving its full-year forecast unchanged.

The yen trading at 76.71 per dollar, near a postwar high, is stronger than its estimate that the currency will average 81 for the full year.