Share prices finished higher on London's Stock Exchange Friday after a calm session. Prices moved up on a good performance in the stock index futures market, but investors then became reluctant to take positions as the weekend approached, dealers said. The Financial Times-Stock Exchange 100-share index was up 5.9 points, or 0.3 percent, at 2,183.4. The Financial Times 30-share index was up 5.9 points at 1,723.8. The Financial Times 500-share index rose 2.46 points to close at 1,152.52. Volume came to 521.3 million shares, compared with 559.3 million shares Thursday.