Blue chip shares struggled for direction ahead of the inauguration of Donald Trump as US president later in the day (20 January 2017). Western markets have been boosted since his shock November victory that has seen him pledge to spend $1trn (£818bn) on infrastructure spending and threaten trade wars.
The FTSE 100 Index slipped two points to 7,206.5, in light trading as investors prepared to watch Trump's keynote speech ahead of a day of ceremony. The FTSE 250 fell 58.8 points to 18,165.
The top flight has fallen over recent days as the pound has gained against the dollar and the euro.
Footsie shares are less appealing to investors when the pound rises because most of the sales of firms in the index are earned aboard, hitting revenues when translated back into sterling.
IG market analyst Joshua Mahony said: "Sterling strength, coupled with a wider degree of scepticism over whether Trump will really deliver has dealt the recent rally a blow."
In the UK, the Office for National Statistics (ONS) said retail volumes dropped by 1.9% month-on-month in December, far below economists' forecasts of a 0.4% decline and the biggest fall since April 2012.
The biggest risers in the FTSE 100 Index were Smurfit Kappa (+50p to 2139p), BT (+8p to 386.1p), Capita (+9.5p to 511p), Whitbread (+62p to 4133p) and CRH (+39p to 2831p).
The biggest fallers in the FTSE 100 Index were Sainsbury's (-6.2p to 261.8p), Barratt Developments (-10.3p to 495.2p), Tesco (-4.1p to 198.5p), Royal Mail (-8.3p to414.2p), AstraZeneca (-82p to4386.5p).
The biggest risers in the FTSE 250 Index were Synthomer (+42.2p to 419.7p), Amec Foster Wheeler (+29.8p to 482.8p), Zoopla (+8.3p to 346.8p) and NMC Health (+34p to 1650p).
The biggest fallers in the FTSE 250 Index were AA (-17.2p to 253.7p), Euromoney (-32p to1152p), IP Group (-5p to184.4p), Ferrexpo (-3.5p to130.6p) and Vedanta Resources (-26p to 999p).