The agency - better known for its consumer and celebrity credentials - is seeking to attract businesses, students and tourists from China following London Mayor Ken Livingstone's decision to target one of the fastest growing economies in the world.
The appointment also addresses concerns that Britain is 'significantly behind' other European countries in taking a share of the Chinese market. France and Germany in particular have taken considerable steps to establish a presence in China.
The move comes after last December's publication of the Enter the Dragon report, in which the GLA identified high output and efficiency as benefits of the Chinese economy.
The brief includes promoting London as a gateway to the UK for Chinese businesses, and the launch of mayoral offices in Beijing and Shanghai.
Freuds will work with interested parties such as investment agency Think London, government body UK Trade & Investment, education group London Higher and VisitLondon.
Freuds recently became the latter's first retained agency (PRWeek, 6 May). MD Fiona Noble said: 'The details of the campaign are at early stages.'
Agencies on GLA's roster were not invited to pitch.
The roster - comprising The Forster Company, Fishburn Hedges, GCI, Good Relations, QBO Bell Pottinger and Trimedia Communications - was not used because of the nature of the contract, a spokeswoman said.