Miners led top-flight stocks lower, after the market delivered its strongest weekly gains in almost four years last week.
The FTSE 100 Index was down 45.18 points to 6,371.98, after jumping more than 280 points last week, or 4.7 per cent - its strongest performance since December 2011.
The market also broke its run of eight days of gains in a row, dragged down by mining as well as banking stocks.
Michael Hewson, market analyst at CMC Markets UK, said:
“Having come off the back of eight consecutive days of gains the FTSE100 has slipped back today as investors decided to take the opportunity to lock in gains in stocks that have seen a significant rebound in recent days.”
Under pressure miner and trader Glencore was the biggest faller in the top flight, down 8p to 121.1p, after it said it had begun the process to sell its Cobar copper mine in Australia and Lomas Bayas copper mine in Chile.
The miner’s house broker Citigroup said these assets are worth a combined total of around £651 million.
The London-listed Swiss-based firm, which has lost around two-thirds of its value this year, recently pledged to investors to make disposals and cut its debt mountain.
Negative mining sentiment also sent Anglo American down 34.8p to 691.7p and Rio Tinto 62.5p lower to 2,537p.