PRWeek understands that the brand, which is owned by Daimler, is looking for ongoing help with project work as it seeks to take a bigger slice of the lucrative UK small car market.
The search is part of a wider marketing initiative to push Smart and comes as sales in 2012 are down 3.3 per cent in comparison with the same period in 2011.
The brief is expected to be focused on consumer work and is thought to be tied in with the relaunch of the brand.
PRWeek understands that Smart is now shortlisting agencies.
Mercedes-Benz, which is part of Daimler and oversees elements of Smart, declined to comment.
However, Mercedes-Benz UK marketing director David George told PRWeek's sister magazine Marketing (11 September) that a broader investment 'marks the start of a reinvigoration' for Smart.
This was, he added, to create a 'spark' and help car buyers 'take note of Smart as a brand again'.
The pitch process is expected to take place during October.
It is unclear whether Fever PR, which currently retains project work around the vehicles, will be affected by the process.
Smart was unveiled in the UK in 2000 and next year will launch the first of its range of electric cars.
Meanwhile, Cake has been brought on board by Honda to help drive its social media work.
The news follows prweek.com/uk revealing on 12 April that the car manufacturer was searching for help in an effort to increase engagement with customers and move away from a corporate online presence.
Cake was picked following a pitch process, which saw an initial longlist of more than 100 agencies whittled down to a final creative shoot-out of four.