Retailer JD Sports Fashion has seen shares tumble after warning over profits following a sales slump in October. Shares in the sportswear firm plunged as much as 17% in morning trading on Thursday after it said underlying annual profits are now expected at the lower end of its previous guidance for between £955 million to £1.04 billion.

It follows tough trading in October, with UK sales hit by mild weather and higher promotional discounts elsewhere in the sector, while JD Sports said North American sales were likely to have been affected by uncertainty ahead of the US election. Like-for-like sales fell 2.4% in the UK overall in the three months to November 2, with US sales of 1.

5%. Same-store sales were 0.3% lower across the group in the quarter.

Regis Schultz, chief executive of JD Sports, said: “After a good start to the period, helped by strong back-to-school sales, we saw increased trading volatility in October, particularly in North America and the UK, reflecting elevated promotional activity and mild weather.” “The trading environment remains volatile though and, following October trading, we now anticipate full year profit to be at the lower end of our guidance range,” he added. The said it saw solid trading in August and September, but this was followed by “much softer consumer demand” in October.

Store sales continued to outperform online trading, while footwear also fared better than clothing, according to the group. JD opened 79 new shops in the third.