Used for:    

• Private-public partnership
• Private-public sector corporation
• Public-private partnership
• Public-private sector collaboration

Narrower term:

• Build-oprate-transfer (Public contracts)

Broader term:

• Cooperation

Public-private Partnerships 

Public-private partnership (PPP) is a funding model for a public infrastructure project such as a new telecommunications system, airport or power plant. The public partner is represented by the government at a local, state and/or national level. The private partner can be a privately-owned business, public corporation or consortium of businesses with a specific area of expertise. 

PPP is a broad term that can be applied to anything from a simple, short term management contract (with or without investment requirements) to a long-term contract that includes funding, planning, building, operation, maintenance and divestiture. PPP arrangements are useful for large projects that require highly-skilled workers and a significant cash outlay to get started. They are also useful in countries that require the state to legally own any infrastructure that serves the public.

(Source:  http://whatis.techtarget.com/definition/Public-private-partnership-PPP)