Rohm Ltd shares plunged up to 16% on Monday, trading 9% lower at ¥3,449 after Denso considered pulling its takeover offer.
Denso Corp, which already holds about 5% of Rohm and supplies Toyota, said it lacked Rohm’s consent and is assessing withdrawal options.
The proposed acquisition, announced in March, valued at roughly $8.3 billion would give Denso a controlling stake in the Kyoto‑based chipmaker.
Rohm is exploring collaborations with Toshiba and Mitsubishi Electric as Japan pushes consolidation in its fragmented semiconductor sector.