SHARES on the London Stock Exchange closed lower yesterday, as Wall Street dipped and the privatised electricity sector gave up much of its spectacular gains from Monday. The FTSE 100-share index closed at 3,449.9, down 13.4 points from the previous close. Volume was 447.4 million shares at 4 pm, down from 491.9 million the same time on Monday. Analysts said a combination of weakness on Wall Street and profit-taking in the privatised electricity sector, which was almost the only supporting factor on Monday, left the London market floundering. Profit-takers took advantage of the solid gains in the sector after Anglo-US conglomerate Hanson's launch on Monday of a huge takeover bid for Eastern Group sparked a frenzy of buying. Southern Electric was down, South Western Electricity and Manweb all fell. Hanson continued to suffer from a negative response to its bid, easing slightly. National Westminster Bank was lower following the release of disappointing interim profits. Rival banking group Abbey National gained.