Practice Areas

  • Civil litigation
  • Commercial litigation


  • Ateneo de Davao University
  • Ateneo de Manila Law School

Mr. Augusto Leon Araneta Macatangay is a Partner in Siguion Reyna, Montecillo & Ongsiako. He joined the firm in October 2009.

Leo specializes in civil litigation and commercial litigation. He has tried a broad range of cases involving contract disputes, corporate rehabilitation, government bidding disputes, intra-corporate controversies, local government tax refund, medical malpractice, family law and settlement of estates, energy regulation, securities transactions, information technology, debt recovery, enforcement of foreign judgments and arbitral awards, insurance claims, labor disputes, and disputes involving land, mining and natural resources.

Leo has handled a variety of notable matters. He represented Atlantic Gulf and Pacific Co. of Manila to close a multi-jurisdictional Syndicated Loan in London, Central Azucarera de San Antonio and Central Azucarera de Bais to secure energy regulatory approvals, Stradcom Corporation in a complex multi-billion intra-corporate controversy involving several cascading companies where shareholdings are disputed on every level; Realtime Data Management Services, Inc. in a government bidding dispute involving the production of Driver’s Licenses for the Land Transportation Office; Philippine Investment Two (SPV-AMC), Inc. a multi-billion Special Purpose Vehicle Corporation for its successful rehabilitation; General Milling Corporation by successfully reducing the judgment award from hundreds of millions to less than a tenth of the award; Unilever Philippines, Inc. in a successful claim for refund of more than two hundred million local government taxes wrongfully imposed; Greenfield Development Corporation in opposing the application of the Comprehensive Agrarian Reform Program; Dole Philippines, Inc. in opposing a multi-million labor claim; Banko Sentral ng Pilipinas in defending its actions against Banco Filipino; Republic Real Estate Corporation in its bid to recover payment from the Republic of the Philippines for the reclamation of a better part of Manila; and Holcim Philippines, Inc. in a multi-million intra-corporate controversy.

Leo is a Member of the Board, Corporate Secretary and consultant to various companies engaged in land transactions, sugar production, logistics, information technology, retail distribution, and media. Before joining Siguion Reyna Montecillo & Ongsiako and after passing the Bar, Leo joined The Bengzon Law Firm. While in Law School, Leo was connected with the Senate of the Philippines under the Office of Senator John H. Osmeña. Also during Law School, Leo was hired by the Office of then Supreme Court Justice Reynato Puno to draft a Treatise on Constitutional Law.

Leo graduated from Ateneo de Davao University with a degree in Economics, cum laude, and with a law degree from Ateneo de Manila Law School, where he was, Juris Doctor, Silver Medalist, Second Honors.

Hailing from Davao City, Leo is the first lawyer in his family. He loves to travel and to spend time with family and friends. While he is not traveling and catching up, Leo enjoys going to the beach, cooking, listening to the Beatles, watching episodes of The Walking Dead, Black Mirror, and reruns of Friends.