Oil companies continue to perform well but electricity companies are hot on their heels. - Major oil companies have maintained their stronghold as the world's most financially effective energy businesses, according to the 2008 Platts Top 250 Global Energy Company rankings (based on assets, turnover, profits and return on investment) published on 20 October 2008. All 250 companies have assets of over 2 billion US dollars. The 2008 rankings show that: 1) companies in the Asia-Pacific region...