The Sensex at the Bombay Stock Exchange opened 45 points lower, at 18,251, this morning, on continued selling by foreign funds, amid weak Asian bourses and political unrest in West Asia. Later, after oscillating between positive and negative territory, in volatile trade, the Sensex stood 22 points, or 0.1 percent in the green, at 18,318, a short while ago. Other regional markets in Japan, China, Hong Kong, South Korea, Singapore and Taiwan were down by between 0.1 percent and 1.5 percent, on mounting concern that instability in West Asia and North Africa may hamper global economic recovery.