TRE COLLI started business in the beginning of the 70s, bringing together the individual experience gained by each of its founding members in the construction sector, specifically in earth excavation and movement for building works.

Since the start of the company in 1971, TRE COLLI has mainly worked on earth excavation and earth moving for the construction of industrial pipelines, in particular oil, gas and water pipelines.
The company's reputation for reliability and its success acknowledged by the largest Italian clients led TRE COLLI to gradually extend its operations to also include the mechanical assembly of complete oil and gas pipelines as well as the relative compression and pumping installations.

Through its professionalism and the experience gained in the pipelines and installations sector, the company set up its own operating structure including a 24/7 maintenance and emergency response service for oil pipelines belonging to the major oil companies operating in Italy (ENI, ERG, Shell, etc.), as well as for other clients of high international standing (NATO), making it today the leader in Italy in this business sector.

The company's consolidated technical and operational abilities as well as its solid financial structure has allowed the company to obtain permission to carry out public works from the "DeloSovim Organismo di Attestazione SpA (Certification Authority)".
Since 1988 it is a Regular Member of the International Pipe Line & Offshore Contractors Association.

To diversify and develop its business in other construction sectors, in 1980 TRE COLLI opened new premises for the production of prefabricated structures and components using the latest technology in standard and
pre-compressed reinforced concrete for industrial, civil and sports buildings and road networks.

Around 80% of TRE COLLI's annual turnover is based on the OIL & GAS market:
in excavations, the transport and laying of pipelines,
and operations & maintenance services for these works.