Housebuilder Persimmon was one of the biggest fallers on Wednesday, losing almost 4% after issuing a poorly received trading update.
It gave few details in its update, but said that sales were “in line with the prior year” and “pricing remains firm across our regional markets”.
Rival builder Barratt Developments also suffered, sliding 2.5%.
By the end of trading, the benchmark 100-share index was almost flat, up 0.22% or 16.61 points at 7,529.72.
Energy firm SSE gave up early gains after it announced it was merging its domestic business with Npower. By the end of the day it had lost 0.9%.
Primark owner AB Foods dropped for a second day, shedding 3.5%. On Tuesday, its shares fell almost 4% after it said that profits at its sugar business were set to fall this year as a result of lower EU prices.
But Marks and Spencer rose, adding 1.6% after announcing its first-half results. Total sales rose 2.6% but pre-tax profit fell 5.3%.
On the currency markets, the pound fell 0.46% against the dollar to $1.31060 and was also down 0.5% against the euro at €1.13080.