The benchmark index retreated from its highest since May 2008.
London's blue-chips started the week on a downbeat note and retreated from four-and-a-half year highs, with falls in Vodafone (LSE: VOD.L - news) and Meggitt shares helping to drag the FTSE 100 (FTSE: ^FTSE - news) lower.
Analyst downgrades hit both companies and the benchmark index lost 0.3pc in early deals, while the mid-cap FTSE 250 (FTSE: ^FTMC - news) was little changed at 13,277 points. Mike van Dulken, head of research at Accendo Markets, argued the FTSE 100 could see further resistance ahead.
"Even if this is a pause before another up move, could 6,400 prove a significant hurdle?" he said, adding that the potential obstacle was "being largely ignored amid all the bullishness".
Vodafone , which is due to update the market on its latest trading on Thursday, was one of the heaviest fallers and lost 1.8pc after Citigroup (NYSE: C - news) analysts advised investors to take profits after the stock's recent strong run. The experts at the broker noted that Vodafone shares have returned 11pc so far in 2013, and cut the mobile giant to "neutral" from "buy".
"We recently reduced our full-year earnings before interest, tax, and amortization forecasts from £401m to £391m, now in line with consensus, because of lower commercial aftermarket expectations," said analysts at the bank. "We expect Meggitt will achieve £391m, but we are not convinced they will beat it convincingly and do not expect material upgrades to 2013."
The UBS scribblers further disappointed investors by arguing a takeover of the company was now unlikely.
At the other end of the table, strong full-year results saw investors chase gold miner Randgold Resources to the top of the FTSE 100. The company said 2012 profit climbed 16pc and boosted its dividend by 25pc, sending the shares up 3.9pc.