The 'Mobile Tate' pavilion will tour the UK from August 2008 to August 2012, as part of a Cultural Olympiad scheduled to finish at the Olympic Park in Stratford, east London, in time for the Games' kick-off.
A Tate spokeswoman said: 'We have nearly finished interviewing a number of shortlisted practices. We have had a number of expressions of interest and we will be announcing a winner shortly.'
It is the first time a portable arts space on such a scale has been attempted in the UK, and it is understood the pavilion will bring art to 'unexpected settings' as well as the Tate galleries in Liverpool and St Ives.
According to a design brief obtained by the AJ, the pavilion will 'make a new space for art, creating a different experience than is possible in a gallery, attracting and engaging people who do not visit museums and galleries'.
The winning practice will be asked to design a hugely ambitious temporary structure; it will need to be easily dismantled while offering a setting for eating and dancing and also providing a minimum 200-seat auditorium space complete with stage.
The demountable pavilion will tour the country during the summer months over a four-year period, acting as a travelling festival for art that will, according to the brief, 'give a sense of the circus is coming to town'.
As well as providing space for exhibitions, the pavilion will need to be capable of growing and shrinking according to the size of the installation, while remaining small enough to be easily transportable.
The winning architect/engineer team will be announced next month, and outline designs are expected by October, ahead of an agreed detailed design by February next year.