Seven years after opening an office in Mexico, high hopes for a growing local economy and an improving outlook for the U.S. automobile industry have led Detroit-based Am Law 200 firm Miller, Canfield, Paddock and Stone to more than double the size of its outpost in the northern industrial city of Monterrey.

Miller Canfield announced Friday an affiliation agreement with 14-lawyer Arizpe, Valdés & Marcos, a Monterrey-based firm formed in 2001 that’s known for its transactional work, particularly in the automotive sector.