Shares in AG Barr PLC (LSE:BAG) dropped 8%, or 52p, to 595p after the maker of Irn-Bru revealed that supply chain failures had knocked an estimated £10 million off first-half revenue.
The soft drinks group said stock availability tightened as the second quarter progressed, driven mainly by internal problems linked to its capacity and capability change programme.
External issues with third-party manufacturing also contributed.
Revenue for the 26 weeks to 1 August is still expected to come in at around £246 million, up roughly 8% on the £228.1 million reported a year earlier.
Operating margin should land in the middle of the guidance range.
The company maintained full-year profit guidance and said it now expects double-digit percentage revenue growth for the year as a whole, helped by a stronger second half.
Irn-Bru left the first half growing faster than the market in both England and Scotland, with the strongest performance in England following the rebranding of Irn-Bru Zero.
Rubicon strengthened through the period on the back of its own rebrand and new product launches.
Boost delivered double-digit growth as it pushed into grocery and entered the healthy hydration category with Boost Water+.
Those gains were partly offset by weakness at Funkin, the cocktail mixer brand, and at Barr Brands.
The integrations of Fentimans and Frobishers, both acquired recently, were completed on schedule during the half, with efficiencies expected to begin showing in the second half.
Production of Boost Sports was insourced to the Cumbernauld factory at the end of the period, and a capacity upgrade at Milton Keynes is progressing to plan.
Chief executive Euan Sutherland said the supply constraints that hit the second quarter were being resolved and that consumer demand remained strong, with all core brands gaining market share.
Panmure Liberum cut its price target 25p to 725p, but remains a 'buyer'.
"We remain positive on the shares given the opportunity to broaden the reach and appeal of AG Barr's core and newly acquired brands, although missing the boost from favourable weather and a summer packed with major sporting events is likely to weigh on sentiment in the near term," the broker told investors.
Peel Hunt added: "The underlying sales run-rate looks strong, with market share gains coming through new product development and distribution. The maintenance of full-year guidance despite these headwinds demonstrates the company's excellent cost control."
It says 'buy' up to 800p.
