After witnessing two sessions of losses, the Bombay Stock Exchange benchmark Sensex today opened higher by almost 69 points at 18,248.The Sensex was trading at 18221, up by over 41 points.The rise in Sensex is due to emergence of fund buying in oil and gas, realty and metal stocks, coupled with firming trend overseas.Meanwhile, the Japanese Nikkei gained 0.31 per cent in the morning trade today, while the US Dow Jones Industrial average ended 0.20 per cent higher yesterday.