Siguion Reyna, Montecillo & Ongsiako

About Us

Our History

Our law firm was founded in 1901, and has a reputation as the oldest continuously operating law office in the country.​

The Philippines at the turn of the 20th century was a colony of the United States. Manila – already a hub of Southeast Asian trade – had become the main American outpost in Asia. Two American lawyers, John W. Hausserman – formerly of the U.S. Judge Advocate General’s Office – and Charles Cohn, were the firm’s founding partners.

In 1903, the Cohn & Hausserman Law Office was appointed the Philippine Branch of the Coudert Brothers, a New York law firm (in a nod to tradition, the firm’s cable address was “TREDOUC” – the reverse of “COUDERT”). When the Coudert Brothers closed their Philippine Branch in 1907, Cohn & Hausserman continued their practice, later merging it with the law firm of Ortigas and Fisher. Hausserman would later establish Benguet Consolidated, the pioneer in Philippine gold mining, while Fisher would become a justice of the Philippine Supreme Court.

In 1923, Hausserman, Ortigas, Cohn & Fisher merged with Kincaid, Perkins & Kincaid, which later became Fisher, Dewitt, Perkins & Brady, after other American partners joined the practice. A notable event occurred in 1936, when Alfonso Ponce Enrile, one of the most noted trial lawyers of his time, became the first Filipino partner, and the firm became known as Dewitt, Perkins and Ponce Enrile. From that time on, the engagement of American lawyers ceased, and the firm evolved to be entirely Filipino.

Leonardo Siguion Reyna and Manuel Montecillo joined the firm in 1948 and became General Partners in 1961. Both Siguion Reyna (“Sig”) and Montecillo (“Monte”) continued practicing until they passed away in 2010 and 2011, respectively. With more than 60 years of active legal practice, Sig and Monte were the longest-serving legal practitioners at the time of their demise. Oscar Ongsiako, the third name partner, passed away in 1995.

Keeping to tradition, our firm’s leadership continues to be lodged with our General Partners. Our Chairman, Rolando Mario Villonco, was elevated to the General Partnership in 1996. Cesar Manalaysay, Mario Andres and Edgardo Balois became General Partners in 2011.

Today, images of our name partners line the walls of our offices – a reminder to our incumbents that we have a legacy of service to live up to, that we belong to an institution that has been an integral part of Philippine business for more than a century, and that we have an obligation to ensure that the tradition of excellence, begun and nurtured by our predecessors, will continue.

Firm Awards and Recognition

SRMO has been recognized as one of the leading law firms in the Philippines for its contribution to the legal profession and quality of service to its clients.




Siguion Reyna Montecillo and Ongsiako is the Philippine member of the TAGLaw international alliance of law firms. The firm also regularly corresponds with several international law firms, and has acted as Philippine counsel for many international transactions. 

Founded in 1999, TAGLaw® is an international alliance of independent law firms. With more than 160 firms in over 90 countries, TAGLaw ranks among the five largest legal alliances globally, and has been consistently recognized as “Elite” in the Chambers Global rankings guide for legal networks (2013, 2015, 2016, 2017, 2018, 2019, 2020).

Visit Us

4th & 6th Floors, BDO Towers Paseo (Formerly Citibank Center) 8741 Paseo de Roxas Makati City 1226, Philippines

Give Us A Call

+63 (2) 8810 0282-90

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