Britain's bluechip index rose to 7142.83 points, 0.3 per cent higher, after a last-minute rally before it closed on today's shortened trading day.
The index has twice closed at record highs this week, finishing above 7,120 points yesterday as rising gold prices pushed miners of the yellow metal higher.
Today a mixed bag of stocks dragged the FTSE 100 higher, with Coca-Cola Hellenic Bottling Company the biggest riser, edging up 1.9 per cent to 1,807 points.
Much of this year's rise has been driven by cheaper sterling, which has pushed the FTSE higher as investors took advantage of comparatively cheap shares.
While the index has risen 13.8 per cent this year, in dollar terms it is still four per cent lower.
But Joshua Mahony, market analyst at IG, warned those records high point to further volatility ahead.
"European markets are looking to close out 2016 on a somewhat downbeat note, with profit taking place amid a market that is largely devoid of liquidity," he said.
"The volatility synonymous with low volumes has been largely missing of late, and instead there has simply been a strong element of indecision.
"With the FTSE 100 having made two attempts at new all-time highs this week, there is a chance that we could start the New Year with both UK and US indices hitting new highs.
"US futures have edged off overnight highs, with the negative tone seen in Europe crossing the Atlantic. It looks like a quiet end to a very busy year, but 2017 certainly promises to be just as eventful."