The FTSE 100 Index eased back from yesterday's gains to stand 3.6 points lower at 5787.4, with trading volumes low ahead of a shortened trading day in the US amid the Thanksgiving celebrations.
Shavaz Dhalla, financial trader at Spreadex, said: "Investor's patience is clearly nearing the end of its tether as Monday's meeting will be the third meeting between Greece and its lenders amidst trying to establish a manageable repayment plan.
"A lack of agreement on Monday could prove 'three strikes and you're out' for investor tolerance over Greece's negotiations."
Miners weighed on the market as the sector lost some of the gains seen in the previous session after figures revealed a bounce back in China's manufacturing sector, sparking hopes for the world's second biggest economy.
Evraz fell 2.6p today to 234.75p and Rio Tinto dropped 22.75p to 2987.25p.
In a quiet day for corporate news, magazine publisher Future lifted 3% or 0.5p to 17.75p after upbeat annual results revealed the fruits of an overhaul to reposition itself as a digital media group.
Future, which publishes magazines such as Total Film, T3 and Classic Rock, posted a 68% leap in annual earnings to £6.9 million and said its embattled US arm would return to profit next year.