The initiative will be led by the LDA but conducted by Team London, a steering group that will include representatives from organisations such as the London Tourist Board and the London Chamber of Commerce.
Vincent Burke, the media manager at the LDA press office, said: "This is part of the economic development strategy, working with the mayor's office, to bring together 20 key organisations to better co-ordinate London's international branding."
At present, the various London bodies use a variety of branding images to market themselves. The LDA is currently talking to around ten agencies, with a view to making an appointment in August.
The London brand and icons will run across the gamut of media, including sales promotional material and direct marketing activities.
Pitching for the task will not pose a problem to agencies on the Greater London Authority or LDA roster. Burke said: "What they are doing is complimentary, to a large extent."
The LDA was established in June 2000 with a brief to co-ordinate the economic regeneration of the city. It has a budget of £300 million.
Media activity on the business is not yet confirmed.