Mayer Brown has made up London construction and engineering specialist Jonathan Olson-Welsh as part of a 21-strong partner promotions round, with fellow US firm Latham & Watkins promoting two City associates to partner in its annual round.

Mayer Brown’s promotions, which are effective from January 2013, include new partners in a range of cities such as Hong Kong, Chicago and Rio de Janeiro, across a range of practice areas such as dispute resolution, banking and corporate.