The area sells brands including Ted Baker, Desigual, Tommy Hilfiger, Firetrap and Nümph.
Store manager Martin McElhinney said the concept had the potential to translate into a standalone store format.
He said: “We had noticed good growth in young fashion and now sales are up 30% against last March. We are looking at the possibility of opening standalone stores. If the [Promise] brand develops, we’ll roll it out.”
Promise will also sell classic casuals, accessories and handbags.
McElhinney said he hoped the new department would give the store an edge over its competitors. “Over the past couple of years we have faced up to the fact that the big UK chains have moved into Ireland,” he said. “You have to continually reinvent yourself. The new area is slightly more cutting edge. We noticed the growth, so we were prepared to put the investment into it.”
The Donegal-based department store was founded by the McElhinney family in 1971, and at 90,000sq ft is one of the largest department stores in the country. The business’s 16 other clothing departments will also receive a new look over the next two years.
The retailer does not operate any concessions and the offer is entirely own bought.
In addition to young fashion brands, it sells a mix of mainstream womenswear brands including Betty Barclay, Bianca and Noa Noa.
It also stocks menswear brands including Gant, Lyle & Scott and Lacoste, and has a tailoring department for men.