AMOCO is a major oil and GAS company that was founded in 1911. It is one of the largest oil companies in the world and has operations in more than 70 countries. The term AMOCO can be broken down into three crossword solutions: GAS (3 letters), ARCO (4 letters), and HESS (4 letters). GAS stands for Gulf American Oil Company, which was the original name of AMOCO. ARCO stands for Atlantic Richfield Company, which was the name of the company after it merged with Atlantic Richfield in 1998. HESS stands for HES Corporation, which was the name of the company after it merged with HES Corporation in 2000.