When Duane Morris partner Eduardo Ramos-Gómez finished helping his firm ink the final version of a joint venture agreement with Singapore-based Selvam to form Duane Morris & Selvam Jan. 1, he urged the firm to turn its attention on international growth to Mexico — and specifically a 15-lawyer Mexico City firm, Miranda & Estavillo.

The selection wasn’t arbitrary. After all, before joining Duane Morris, Ramos-Gómez was Mexico’s ambassador to Singapore. From 1980 to 1984, he was an associate at Miranda & Estavillo, a firm he introduced to Duane Morris when he joined in 2004. After a few years of a relationship Duane Morris Chairman John Soroko described as one of friendship, resources and referrals, the two firms have now decided to make it more official, formalizing a cooperative relationship or alliance.