MUMBAI, DEC 7: Pivotals continued to rule firm on the Bombay Stock Exchange (BSE) today on hectic purchases by foreign funds coupled with short-covering by operators. Infosys and Pentafour Software led the rally on fresh buying.Sensex (BSE sensitive index) opened substantially higher at 4891.47 and moved in a narrow range of 4893.47 and 4850.37 before being closing at 4864.62 with a net gain of 28.64 points against yesterday's close of 4835.98. The BSE-100 index gained 24.02 points to 2387.91 from the previous level of 2363.89. Brokers said the sentiment continued to be better following purchases by foreign funds and speculators but some gains were pruned on late position unwinding in view of last session of the current settlement on the National Stock Exchange (NSE). Software shares continued to remain the market leaders but interest was also seen in cement shares. Pentafour Software was the most sought after stock following the news that the company has proposed to hive off its software division andfocus on multimedia. The market seemed to have reacted positively on the news and the share was locked at the day's best permissible level. The recently favoured bank shares were losing shine on profit-taking.Trading ended at 4.15 pm at the BSE in accordance with the rival bourse NSE which was forced to extend the trading session till that time due to some technical snag.