By Amber Murray Delays in summer stock reaching stores due to Red Sea shipping disruption contributed to sales at Poundland owner Pepco slumping over its latest quarter. The retail group, which also runs the Pepco and Dealz brands across Europe, has reported that its like-for-like sales dropped by 4.3 per cent over the quarter to June 30. The sales slump was even greater across its Poundland stores, which reported a 6.9 per cent drop in like-for-like sales. The company said this was largely due to challenges linked to the launch of new clothing and general merchandise ranges from its Pepco bus…