Eight agencies were originally involved in the pitch. The account is worth an estimated £10 million in the UK.
Despite reports in the French press that CLM BBDO has already scooped the account, further presentations are scheduled for later in the month and a decision is not expected for the next three to four weeks.
Olaf Goettgens, the Mercedes-Benz worldwide marketing director, is overseeing the review.
A spokeswoman for Mercedes-Benz said: "We initially invited eight roster agencies from around the world to come up with the best idea for the launch of the Mercedes C-Class model. We have chosen the three best concepts."
The C-Class launched in 2000 and is one of Mercedes-Benz's biggest-selling cars. The company has sold 2.1 million of the vehicles.
- Opinion, p17.