Denso withdraws Rohm bid as three-way merger takes hold

Denso Corp is considering withdrawing its takeover proposal for Japanese chipmaker Rohm after failing to secure the company’s agreement, Reuters reported on 27 April. The Toyota supplier first submitted the bid back in February, a move that would have brought Rohm’s silicon carbide power semiconductors under the direct control of an automotive player.

Rohm apparently concluded that becoming a Denso subsidiary would tilt its business at the expense of its relationships with other vehicle component makers that compete directly with Denso. The chipmaker’s outside directors, convened as a special committee to evaluate the offer, judged that the synergies Denso anticipated would be difficult to realise on those terms.

Rohm’s preferred path has taken shape separately: in late March Rohm, Toshiba, and Mitsubishi Electric announced discussions toward merging their power semiconductor operations—a three-way tie-up that has progressed in parallel to Denso’s unresolved offer. If completed, it could significantly complicate any plans to become a subsidiary under Denso, which primarily supplies and is partly-owned by Toyota Group.

Rohm’s willingness to accelerate the Toshiba-Mitsubishi Electric talks instead of playing into Denso’s vertical integration bid reveals the extent to which the chipmaker values its cross-industry customer base. That preference, which comes at the expense of a well-funded acquirer, could be indicative of how Japan’s power chip industry consolidation will actually play out—instead of vertical integration in favour of automotive, there is horizontal consolidation among peers. 

A combined Rohm-Toshiba-Mitsubishi Electric entity would command roughly 11% of the global power semiconductor market, placing it second behind Germany’s Infineon Technologies. The rationale behind such a bid is straightforward: Japanese chipmakers have collectively ceded ground in recent years as Chinese competitors mount an intensifying low-price push across silicon carbide and adjacent technologies.

Denso entered the negotiations already holding a roughly 5% stake in Rohm, acquired through a strategic partnership announced back in May 2025. The withdrawal, if confirmed, would leave Denso without the secured advanced chip supply it sought. Across the automotive industry, in-house semiconductor production is a growing priority; one need only look at the Tesla Terafab project to observe this trend.

The Rohm acquisition bid sits within a broader campaign by Toyota Group to simplify its supply chain and governance arrangements. The automotive conglomerate successfully fended off activist investors in the form of Elliot Investment Management to take Toyota Industries private, although this came at a substantial 26% premium relative to its original offer.