The benchmark index sank by one per cent on the open and stood at 6,262 in the first hour of trading - wiping off gains made earlier in the week and putting the recent highs of 6,400 a long way off.
International Airlines Group (IAG) was one of the worst performers as it dropped four per cent after warning that the aftermath of the Brussels attacks could hit its plans for expansion in the second quarter.
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Royal Bank of Scotland was also in the red after it announced losses of £968m in the three months to March. Investors took a few minutes to digest the news, but eventually decided a near-billion pound black hole wasn't a good story. Shares dropped by more then two per cent to 239p.
After fears of a stumble, oil prices showed signs of life this morning as well, as Brent Crude added a modest 0.3 per cent to take it to $48.28 a barrel - nearly 10 per cent up on the week.