Y Bhg Tan Sri Dato Sri Mohd Hassan Marican, a Fellow of the Institute of Chartered Accountants in England and Wales, as well as a member of the Malaysian Institute of Accountants and the Malaysian Association of Certified Public Accountants, was born in Sungai Petani, Kedah in 1952.

He received his early education from Sekolah Rendah Ibrahim in Sungai Petani and secondary education from Malay College Kuala Kangsar. He left for London in 1972 to join accounting firm Touche Ross & Co as an article clerk before qualifying as a Chartered Accountant and appointed to become the firm's Audit Manager.

Tan Sri Hassan returned to Malaysia in 1980 to work with Tetuan Hanafiah Raslan & Mohamad / Touche Ross & Co. - Public Accountants and became a partner a year later. In 1989, he was "called" to serve the National Oil Corporation PETRONAS as Senior Vice President, Finance. He was appointed President and Chief Executive Officer of PETRONAS in February 1995.

Tan Sri Hassan has received numerous awards, among them are the Panglima Setia Mahkota (PSM) in 1997 carrying the title Tan Sri; the Bintang Darjah Seri Paduka Mahkota Terengganu (SPMT) in 1996 and Darjah Sultan Mahmud Terengganu Yang amat Terpuji (DSMT) in 1992, both carrying the title Dato'; and the Panglima Negara Bintang Sarawak (PNBS) in 2003 which carries the title Dato Sri. The French Government has awarded him the "Commandeur De La Legion D'Honneur" in 2000 and the Vietnamese Government has awarded him the "Friendship Medal" in 2001. Universiti Malaya awarded him with Honorary Doctorate in Engineering in 2001.

Tan Sri Hassan is a member of the PETRONAS Board of Directors, and is Chairman of three public listed companies under the Group, namely PETRONAS Dagangan Berhad, PETRONAS Gas Berhad and Malaysia International Shipping Corporation Berhad. He is also the Chairman of Engen Limited, South Africa's leading oil refining and marketing company which is a subsidiary of PETRONAS. Tan Sri Hassan was a member of the board of Perbadanan Kemajuan Negeri Kedah from 1986 to 1994 and was also a council member of Majlis Amanah Rakyat (MARA). He was a panel member of the Malaysian Accounting Standards Board which oversees accounting standards in Malaysia, and was also a member of Kumpulan Wang Amanah Pencen's investment panel.

Beyond PETRONAS, Tan Sri Hassan is a board member of the Malaysia-Thailand Joint Authority, which ofebseec `edroleum development in the overlapping area between Malaysia and Thailand. He is also a member of the International Investment Council for the Republic of South Africa. The International Investment Council was established by President Thabo Mbeki to draw upon insights and wisdom of distinguished international business leaders to provide advice to the President on how to meet the challenges of economic growth and development of South Africa. Tan Sri Hassan is also a member of the Commonwealth Business Council and the World Economic Forum's Council of 100 Leaders.