Martineau Johnson has won the right to protect BMW's brand image in the UK.
William Barker, intellectual property partner at the Birmingham-based firm, says that the contract came after an internal reshuffle at the German company, and was awarded because of Martineau Johnson's success in defending the Rover name.
Rover, which has been bought out by BMW, has used the firm since the mid 1990s and Barker says that they have enjoyed a good relationship.
Since taking on the new role for BMW his team has already issued a claim against a business registered under the names BMW/Rover and Rover/BMW without authorisation.
Barker says: "When Rover's trademark department was closed down in November 1999 all the work went to BMW's in-house legal team.
"Following on from that, we have now been told we will be doing Rover and BMW's work in the UK."
He adds: "BMW could have gone to a City firm, but in Birmingham our salaries are lower than in London, and those savings can be passed on. Wragge & Co has had particular success in getting work which would otherwise go to a City firm, for example, and also have Rover as a client.
"Through our work with Rover we had demonstrated we possessed the expertise and experience to protect a major car firm."