Profit taking saw the FTSE 100 fall 1.3% to 5316.22 points this morning, negating some of its 5.2% rise on Monday.
Optimism on the economic recovery led by US retail data from March led most Asian stocks to gain slightly on Friday.
The FTSE traded 56 points, or 1%, lower this morning at 5705.49 after a downbeat assessment of the US recovery from former Federal Reserve chairman Alan Greenspan.
Most Asian stock markets showed gains on Wednesday, on the back of the latest US job data.
The FTSE 100 was marginally up in early trading, by 0.06% or 3.41 points to 5,748, only a few hours before the Prime Minister Gordon Brown is expected to call a General Election for 6 May.
The FTSE was up in early morning trading at 5717.92, rising 38.28 points (0.67%).
The FTSE rose by 0.3%, or 14 points, to 5686.32 this morning, buoyed by fighting talk from British Sky Broadcasting.
The FTSE 100 opened higher Tuesday, tracking strength overnight on Wall Street, as Legal & General (L&G) beat profit forecasts and lifted its final dividend payout by a third.
The FTSE was modestly lower in early Thursday trade following reports Greece may yet seek financial aid from the IMF because of disillusionment over the prospects of help from the EU.
The FTSE 100 was up 0.65% or 36.43 points to 5,630 early this morning as the rumoured RBS debt restructuring boosts financial stocks.