Consortium

A consortium (which may also be called syndicate) is formed by two or more independent companies, individuals, or other economic actors that work together for a limited amount of time, usually to fulfill a purpose. Consortia are common in the building industries, roads and bridges are often built by consortia.
Overview.
Very broadly speaking there are two kinds of consortia:
The term can be traced to the 16th century, where it developed from "con sortes", which is the plural of Latin "consors". It can roughly be translated as "united by fate". The english word consort probably has the same origin.
The company Airbus started as a consortium of different companies with the aim of building airplanes. 
In 1970, they officially formed a "groupement d'intérêt économique" (which is a consortium, in the French legal system). Today, Airbus is a Societas Europaea, a shareholding company under European law. Not all consortia are done for profit: The Unicode consortium wants to promote the Unicode standard. It is a non-profit organisation, based in California.