While New Zealand Prime Minister John Key and US Trade Representative Mike Froman led the ceremony at Auckland's Sky City Convention Centre, protestors blocked roads outside.

The ambitious pact aims to break down trade and investment barriers between countries comprising about 40 percent of the global economy.

US President Barack Obama immediately hailed the signing, saying the TPP would give the United States an advantage over other leading economies, namely China.

However, protesters argue it will cost jobs and impact on sovereignty in Asia-Pacific states.

Although the signing marks the end of the negotiating process, the member countries still have two years to get the deal approved at home before it takes effect.

The agreement was signed by Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, the United States and Vietnam.

Groups opposed to the TPP have expressed concern about the secrecy in which the negotiations were conducted, the potential erosion of a country's sovereignty and say it is weighted in the United States' favour.

Latest News  from Business News Desk