Técnicas Reunidas, S.A. (Spanish pronunciation: [ˈteɣnikas rewˈniðas], meaning "Gathered Techniques"), or TRSA, is a Spanish-based general contractor which provides engineering, procurement and construction of industrial and power generation plants, particularly in the oil and gas sector.

[3] The firm has also moved increasingly into the Middle East,[4] and in January 2009 was awarded a $1.2 billion contract to develop two onshore fields in the UAE for a subsidiary of ADNOC.

The areas of activity covered by TRSA's companies are: the petrochemical industry, heat transfer, cogeneration and renewable energies, fertilisers and inorganic chemistry, environmental engineering, iron and steel plants, metallurgy, mining and hydrometallurgy.

The company's R&D Centre, located in Madrid, Spain, is equipped with laboratory facilities and pilot and demonstration plants designed to be adapted to different process configurations.

The R&D division develops new processes and the technological and economical improvement of existing ones, applying techniques and procedures of disciplines such as hydrometallurgy and electrochemistry.