London’s blue chip index gained more than £17bn, buoyed by signs of the returning health of the US economy.
The top flight index surged through the 6200 mark after the US government was given another three months to pay its bills by House of Representatives, which voted to suspend the US debt ceiling.
A raft of better than expected purchasing managers’ manufacturing figures, including in the US, also contributed to the bullish mood, helping the FTSE 100 Index close up 67.3 to 6264.9 - a new landmark since May 2008.
The Dow Jones Industrial Average also opened higher after figures showed the number of Americans seeking unemployment benefit last week fell to its lowest level in five years.
The pound was down against the US dollar and the euro at 1.57 and 1.18 respectively ahead of figures on Friday which are expected to show the UK economy contracted in the final three months of 2012.
The biggest FTSE 100 risers were CRH up 68p to 1342p, International Consolidated Airlines Group ahead 10.1p to 218.4p, United Utilities 30p higher at 747.5p and Croda International up 79p to 2437p.
The biggest FTSE 100 fallers were Aggreko down 58p to 1761p, Wood Group off 11p to 824.5p, Morrison 2.2p lower at 257p and Capita down 6.5p to 793p.