Strabag acquisition of Stumpp group cleared with condition

Bundeskartellamt Press Releases

Filed March 2nd, 2026

Detected March 13th, 2026

Summary

The German Bundeskartellamt has cleared Strabag's acquisition of the Stumpp group, a road construction company. The clearance is conditional on Stumpp selling its asphalt mixing plant in Zimmern to a third party before the merger is implemented to prevent market dominance.

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What changed

The German Bundeskartellamt has cleared Strabag AG's acquisition of the Stumpp group, subject to a condition precedent. The condition requires Stumpp to sell its asphalt mixing plant in Zimmern to an independent third party before the merger is finalized. This action is necessary because the combined entity would have held nearly half of the roller-compacted asphalt market in the region between Stuttgart and Lake Constance, raising competition concerns.

Strabag and other regulated entities in the road construction sector should note that mergers leading to significant market share increases, particularly in regional markets for materials like asphalt, will be scrutinized. The Bundeskartellamt's decision highlights the importance of maintaining sufficient competition and ensuring alternative suppliers remain available. While this decision is not final and can be appealed, the condition precedent must be met for the merger to proceed as approved.

What to do next

Ensure the sale of the Zimmern asphalt mixing plant to a suitable third party is completed before implementing the Strabag-Stumpp merger.
Verify that the acquiring third party can ensure the long-term operation of the Zimmern mixing plant.
Monitor potential appeals to the Düsseldorf Higher Regional Court.

Source document (simplified)

Current contents of the Federal Cartel Office

Merger of road construction companies: Strabag’s acquisition of the Stumpp group cleared subject to a condition precedent

02.03.2026

published on: 02.03.2026

The Bundeskartellamt has cleared the acquisition of all shares in the Stumpp group, Balingen, which operates in road construction in the south of Baden-Württemberg, by Strabag AG, Cologne, subject to a condition precedent requiring Stumpp to sell its asphalt mixing plant in Zimmern to an independent third party before the merger is implemented.

Andreas Mundt, President of the Bundeskartellamt: “Strabag is one of the leading road construction companies in Germany and operates a dense network of asphalt mixing plants producing roller-compacted asphalt. The complete takeover of the Stumpp group, including its two mixing plants, would strengthen Strabag’s market position in the area between Stuttgart and Lake Constance to such an extent that it would account for nearly half of the roller-compacted asphalt sold in this region. The sale of the Zimmern plant ensures that sufficient alternatives remain available in the region.”

Roller-compacted asphalt is a key building material for road construction. It is produced in mixing plants and, due to its handling properties, must generally be laid shortly after production. Transport distances are therefore limited for technical and economic reasons. Accordingly, the affected geographic markets are to be defined on a regional basis.

In the region between Stuttgart and Lake Constance, Stumpp is one of the leading road construction companies. It operates two asphalt mixing plants in Zimmern and Balingen and holds stakes in various quarries.

The Strabag group is one of the largest construction companies in Europe. It also has several asphalt mixing plants and stakes in quarries in the region affected by the proposed merger. In the road construction sector, Strabag is currently not a leading provider of services in Stumpp’s field of activity.

The notified merger would make Strabag a major provider in the regional market for roller-compacted asphalt, with market shares well above the 40 per cent threshold for the presumption of market dominance. Four of Strabag’s and Stumpp’s mixing plants in the relevant area are conveniently located along central transport routes, complementing each other particularly well in terms of location. The remaining competitors, mainly medium-sized companies with significantly lower financial resources, each achieve market shares of less than 15 per cent. The merger would also have significantly improved Strabag’s market position in the upstream market for crushed natural stone and, in particular, in the regional downstream market for road construction services.

To dispel the Bundeskartellamt’s competition concerns, the companies involved proposed to sell the Zimmern mixing plant to a suitable and independent third-party before implementing the merger. The Bundeskartellamt thoroughly examined this proposal as part of a market test and consulted other market participants operating in the region. The examination showed that the sale of the mixing plant is generally capable of preventing Strabag from gaining a dominant position in the regional market for roller-compacted asphalt. Without the Zimmern plant, Strabag’s market share will remain well below the 40 per cent presumption threshold. The competition concerns can be fully dispelled if the parties find a suitable acquirer which, among other preconditions, can be expected to ensure the long-term operation of the Zimmern mixing plant.

The Bundeskartellamt’s decision is not yet final. It can be appealed to the Düsseldorf Higher Regional Court.