Marti Group

The Marti Group is a Swiss construction company, consisting of over 80 subsidiaries, officially owned by Marti Holding AG. Besides Switzerland, they are active in neighboring countries such as Germany and Austria, and also outside of Europe such as China and Chile. The company is known for high-profile public and private sector projects and using innovative technologies. Their areas of expertise include building construction, construction and renovation of tunnels, road construction, hydraulic engineering, and other types of civil engineering. They're estimated to be the second largest construction company in Switzerland by revenue and number of employees, only surpassed by Implenia.

Major projects
Tunnel construction:
 * Expansion of the Gubrist Tunnel by building a third tunnel
 * Expansion of the Petersberg railway tunnel in Germany, such that the tunnel was in service during construction
 * Building an access tunnel to the Gotthard Road Tunnel
 * Section of the Brenner Base Tunnel, one of the longest railway tunnels in the world
 * Excavation of the Eppenberg Tunnel to double the capacity of the Olten-Aarau line
 * Underground works on CERN's Large Hadron Collider

Skyscraper construction:
 * Prime Tower in Zürich, the tallest building in Switzerland from 2011
 * Roche Tower 2 in Basel, the current tallest building in Switzerland

Marti was one of the contractors involved in the Astra Bridge, which is a bridge that can be installed over a motorway, such that roadworks can be carried out under the bridge while there is uninterrupted two lane traffic right above them. This type of construction was the first of its kind. The bridge has a modular design, its parts can be carried by regular trucks and it can be installed in a matter of days.

Controversies
In 2020, Marti was accused that their handling of construction waste resulted in fish deaths in the Blausee since 2018. Marti denied the accusation, saying that what they did was allowed by the authorities and it wasn't the cause of the fish deaths. the case is pending in Swiss federal court.