Hope that politicians will this week thrash out a package of measures to rescue the eurozone saw world markets make nervous gains today.
The FTSE 100 index pushed 1% higher ahead of a key meeting on Wednesday when politicians are finally expected to agree a raft of measures to help shore up the currency bloc's finances.
Traders were encouraged by reports that progress had been made over the weekend to agree 108 billion euro (£94 billion) programme to recapitalise banks.
But two crucial decisions are still yet to be taken, including measures to increase the firepower of the bail-out fund from 440 billion euros (£382.9 billion) and letting Greece off repaying some of its debts.
Elsewhere, the Dow Jones Industrial Average in New York was up 0.7% and the Dax in Frankfurt and the CAC 40 in Paris rose about 1%.
At one point, London's blue chip shares lost earlier gains and dropped into negative territory as investors struggled to predict whether the politicians would finally be able to get to grips with the problems, which have haunted markets for months.
But the rally gathered strength again, with banks and miners leading the index higher.