Leading blue chips closed just off their session highs, as investors took heart from Wall Street's advance ahead of the first anniversary of the Sept 11 attacks, albeit in thin volumes as investors kept to the sidelines, dealers said.
Though the prospect of imminent military strikes receded somewhat after Britain's Prime Minister Tony Blair said Iraqi president Saddam Hussein should be dealt with through the United Nations, warnings of possible attacks on oil tankers in the Middle East continued to unsettle, they added.
The FTSE 100 index closed 113.1 points higher at 4,175.5, only just off its peak at 4177.6; all the wider indices were also positive but volume was thin, with a mere 2.04 billion shares changing hands in 122,920 deals.
Meanwhile, in New York the DJIA was up 39.95 points to 8559.53 and the Nasdaq composite was up 9.30 at 1,313.90 at the time.