Atty. Fruto obtained his Bachelor of Laws degree in 1961 from the Ateneo de Manila University, and was admitted to the Philippine Bar on February 22, 1962.
Formerly, he was a partner in the law firm of Feria, Feria, Lugtu & La O’ and the Oben, Fruto & Ventura Law Office and a professor of law in the Ateneo de Manila University and the Lyceum of the Philippines.
Aside from specializing in corporate law, he handled trial and litigation work before the Metropolitan Trial Courts, Regional Trial Courts, the Sandiganbayan, the then Juvenile & Domestic Relations Court, the then Court of Industrial Relations, the then Land Transportation Commission, Labor Arbiters, administrative bodies like the Securities and Exchange Commission, covering civil cases (contracts, commercial transactions, maritime, estate, family relations, transportation, and other civil cases), labor cases and administrative proceedings. He also had extensive appellate practice before the Court of Appeals and the Supreme Court. He also served as a Consultant of the Securities and Exchange Commission.
In 1986, after the People Power Revolution, he joined the government as the Chief Legal Counsel and Senior Vice-President of the Development Bank of the Philippines in February 1987 and later on as Undersecretary of Finance in March 1990, supervising the Bureau of Internal Revenue and the Bureau of Customs. During his stint in government, he also served as Vice-Chairman of the Garments and Textile Export Board; Commissioner of the Export Processing Zone; Director of the Private Development Corporation of the Phils.; Chairman of the Board, Capitol Development Bank; Board Member of the Ninoy Aquino International Airport Authority; Board Member, Mactan International Airport Authority; Deputy General Counsel of the Davide Commission; and Chief Legal Counsel of the Feria Fact Finding Committee created to investigate the Garchitorena land scam. In 1991, he was the Bar Examiner for Taxation.
He served as a member of the Board of Directors of several corporations, among which are the Development Bank of the Philippines, DBP Management Corporation, Local Government Unit Guarantee Corporation and Philippine Asia Life Assurance Corporation, Vice-Chairman of Anchor Savings Bank and ex-officio director of the Philippine Long Distance Telephone Co. He was also Vice-President of Wallem Philippines Shipping, Inc. and Wallem Maritime Services, Inc. He also served as member of the Board of Trustees of the Knights of Columbus Fraternal Association of the Philippines, Inc., and member of the Executive Council of the All Asia Bar Association and the Ateneo Law Alumni Foundation, Inc. He was also President and presently a member of the Council of Advisers of the Philippine Bar Association, the oldest and largest voluntary organization of lawyers in the country.