Tengku Razaleigh Hamzah
Khoo was mentored by Khoo Teck Puat, who founded Malayan Banking in 1960. Khoo joined the new bank and soon became a manager. In 1965, he was seconded to Bank Bumiputra, and quickly rose to a senior position. In his ten years there, he built relationships with Tengku Razaleigh Hamzah, Robert Kuok and Tan Koon Swan.