The luxury brand Mulberry Group saw its shares tumble almost 30% after it issued a profit warning over the impact of the administration and acquisition of House of Fraser by Sports Direct.

Mulberry, known for its designer handbags, operates 21 House of Fraser concessions across the UK and said it expects the collapse of the department store would result in £3m in potential costs for the six months to 30 September.

Since it reported in June, it said the UK market had been challenging and sales in House of Fraser stores had been particularly affected, warning if the trend continued then Mulberry’s full year profit “will be materially reduced”.