FTSE 100 led higher by Admiral Group
(Close): The FTSE 100 reversed its earlier gains by closing down 17 points, or 0.27%, at 6,130.46.
Shares in Admiral Group, the insurer, were the biggest risers after the company reported better than expected annual results.
They closed up 9%, or 159 points, to end the day at 1919p.
The company - which also owns the Confused.com price comparison website - were helped by an 11% rise in profits from car insurance.
But shares in Whitbread fell 6.15% after the firm said sales growth had slowed at its Costa coffee chain.
Like-for-like sales at Costa rose by just 0.5% in the 11 weeks to 11 February, which Whitbread blamed partly on the "unusually warm winter".
Contrasting house price reports from the Nationwide Building Society and Halifax did nothing to calm worries about the sector.
House builder Persimmon saw its shares fall 6.8% to 1998p.
News of weak growth in the UK's services sector weighed on the pound, with a survey registering the slowest rate of growth in the sector for nearly three years.