Primark has reported a healthy sales rise for the last four months of 2015, but margins were hit by the strong US dollar.

Sales in the 16 weeks to January 2 at constant currency rates were up 7%. Based on actual exchange rates sales climbed 3% due to the weakening of the euro against sterling, the retailer’s parent Associated British Foods said.

At Primark the “like-for-like sales performance in the first seven weeks of the financial year was strong, benefiting from comparison with a weaker performance in the prior year when the autumn was unseasonably warm”, the company said.

“In the following nine weeks, like-for-like sales were weaker as a result of warmer and wetter weather across Europe, leading up to and over the Christmas period.”

It added: “As expected, the impact on like-for-like sales of new store openings in northern continental Europe was much reduced, and total sales in this region were well ahead of last year.”

The drop in margins was “lower than initially envisaged as a result of both an excellent performance from our buying teams and a lower level of markdowns arising from a well-managed stock position”, the retailer said.

Primark, which launched in the US in September, said it expects to open six more stores in the country this year.