Shares in Next fell more than 7% in early trade after the fashion retailer issued a cautious trading update.
Next said third quarter trading had been “extremely volatile”, adding that this volatility made it hard to determine any underlying sales trend.
Online sales growth at Next’s Directory business continued to offset falling sales on the High Street, with sales up 1.3% overall in the quarter.
Shares in rival retailers were also hit by Next’s update, with M&S down 3.7%.
Primark owner Associated British Foods dropped 2.6%, while Debenhams fell 2.3%.
However, the wider market was up, with the benchmark FTSE 100 index up 29.15 points at 7,522.23.
Paddy Power Betfair was the biggest riser in the index, climbing 4%, after it reported higher third-quarter revenues and made a small increase to its full-year earnings forecast.
Revenues in the three months to 30 September rose 9% to £440m, and it now expects underlying earnings to be between £450m and £465m.
On the currency markets, the pound rose 0.1% against the dollar to $1.3303 and was 0.2% higher against the euro at €1.1424.