Atty. Sison served as Chairman and President from March 2001 until June 2002, as its President from June 2002 until October 2002, and again, from January 11, 2011 until today. In 2011, he was appointed as President of the Alabang-Sto. Tomas Development, Inc., a PNCC subsidiary, and continues to serve in that capacity until today.

In 1987, he served in the Presidential Multi-Sectoral Task Force in Fiscal Planning under then Secretary of Finance Jaime V. Ongpin. He successfully launched a nationwide consciousness-raising project encouraging consumers to demand official receipts for purchasing to ensure better tax collection. This project, “RAFFLE” is still in force, and continues to grant prizes in millions of pesos to lucky participating consumers.

He served as the Chairman of the Philippine Retirement Authority from August 1992 up to June 10, 1998. He presided over the transformation of the PRA by successfully reorganizing it to become a Center of Excellence in a year’s time, and as a result, PRA was voted as the “The Number 1 Retirement Destination in the World” in 1997. He contemporaneously served as Presidential Assistant for Legal & Judicial Affairs, with the rank of Undersecretary, in the Office of the President from July 15, 1992 until June 30, 1998.

He served as CEO of the Eastern Telecommunications, Phils, Inc. from March 1996 until August 1998. He was instrumental in facilitating the settlement of the government claim over the Marcos ill-gotten wealth issue.

Atty. Sison is a Trustee / Execom Member of the Ramos Peace and Development Foundation, Inc. from 1998 until today. He is also a Trustee / Founder of the Foundation for Judicial Excellence from September 1990 to present. He is the Chairman of the Evelio Javier Foundation from 1990 until today. He actively participated in the National Citizens Movement for Free Elections and has served in various capacities since 1984.

President Sison earned his B.S. Political Science degree in 1963 & his Bachelor of Laws degree from the Ateneo de Manila University in 1967. He passed the Philippine Bar in the same year.