BONN, Germany, March 2, 2026 — The German Federal Cartel Office (Bundeskartellamt) has cleared Strabag AG’s acquisition of the Stumpp Group subject to the divestment of an asphalt mixing plant in Zimmern to an independent buyer.
The transaction concerns Strabag’s planned purchase of all shares in Balingen-based Stumpp, a road construction company active in southern Baden-Württemberg. Stumpp operates two asphalt mixing plants in Zimmern and Balingen and also holds interests in quarries in the region.
According to the authority, the full takeover would have significantly strengthened Strabag’s position in the regional market for rolled asphalt between Stuttgart and Lake Constance. The combined operations would have resulted in the company controlling nearly half of the asphalt marketed in the region, exceeding the legal presumption threshold for market dominance of 40%.
“Strabag is one of the leading road construction companies in Germany and operates a dense network of asphalt mixing plants,” Bundeskartellamt President Andreas Mundt said. “With the complete takeover of the Stumpp Group and its two plants, Strabag would have become extremely strong in the region between Stuttgart and Lake Constance. By requiring the sale of the Zimmern plant, we ensure that sufficient alternatives remain available in the region.”
Rolled asphalt is a key input for road construction and must typically be installed shortly after production, which limits transport distances and makes competition largely regional.
The Bundeskartellamt concluded that the proposed merger would have significantly strengthened Strabag’s market position not only in the regional asphalt market but also in upstream markets for crushed natural stone and in downstream road construction services.
To address these concerns, the parties offered to sell the Zimmern asphalt mixing plant before completing the transaction. Following a market test involving other regional market participants, the authority found that the divestment would be sufficient to prevent the creation of a dominant position.
Without the Zimmern facility, Strabag’s market share would remain well below the statutory presumption threshold for market dominance, provided the plant is sold to a suitable buyer capable of ensuring its continued operation.
The Bundeskartellamt’s decision is not yet final and may be appealed before the Düsseldorf Higher Regional Court.
