Domino’s Pizza (LON:DOM) announced on Tuesday that it expects its annual pre-tax profit to be at the lower end of its guidance. Despite the strong UK performance, its international sales have been weak. Shares in the food outlet slid 7% following the announcement.

UK system sales were up 6% and UK like-for-like sales increased by 4.5%. The company has said that it experienced its busiest ever week in the run-up to Christmas. On the Friday before Christmas, Domino’s sold over 535,000 pizzas in the UK. This is equivalent to 12 a second across a 122-hour trading day.

Domino’s also had a strong digital performance as online sales grew 10.8%.

In April, Domino’s reported yet another strong quarter.

The company has announced that it now has 1,261 stores group-wide. It created over 2,000 jobs as 25 new stores opened in its fourth-quarter, and 59 in the UK and Republic of Ireland in 2018.

However, the strong UK and ROI performance was offset by weaker sales internationally. The company experienced weak international sales progress and business integration challenges in Norway. As a result, full year underlying pre-tax profit is expected to be at the lower end of its expectation range of £93.9 million – £98.2 million.

Chief Executive of Domino’s, David Wild, commented on the results:

“I’m pleased with the continued strong performance in the UK and Ireland, where we opened a further 59 stores. Many families decided to kick off the festive season with a Domino’s, with the Friday before Christmas breaking all records as we sold more than 535,000 pizzas – equivalent to 12 every second.”

“Our international businesses offer significant long term potential, but we have experienced growing pains this year, particularly in Norway, where we have faced business integration challenges. Looking ahead, we will invest further in robust teams and infrastructure in our newer markets, to create a solid platform for profitable growth.”

“The UK delivered food market is vibrant and we estimate that it will grow at a compound rate of 8% a year to 2022. We aim to maintain our share of this market, thanks to over 30 years of experience in delivery, a leading brand, great-tasting pizza and superior franchisees.”

Shares in Domino’s Pizza Group plc (LON:DOM) were trading at -7.16% as of 10:23 GMT.