Mike Ashley's Frasers Group has bought the anchor building at Foyleside Shopping centre in Londonderry previously occupied by Debenhams.
The off-market deal will see the opening of a new Frasers department store next year - similar to its anchor store at Victoria Square in Belfast.
Debenhams has been in administration since April.
It has been unable to find a buyer putting hundreds of NI jobs at risk.
Debenhams has five outlets which are all large tenants in shopping centres in Belfast, Craigavon, Newry, Ballymena and Derry.
Frasers Group is owned by Sports Direct's Mike Ashley who had shown interest in buying Debenhams on a number of occasions.
Paul Wilson, Director of Retail at Savills who brokered the deal said: "Knowing the limited pool of end-users for this space and that Debenhams' business was likely to enter a company voluntary arrangement (CVA), we pursued Frasers and successfully struck a deal to sell the freehold interest.
"The Debenhams CVA gave Frasers the ability to secure vacant possession from a landlord break clause, but a liquidation will speed the process".
He said bringing Frasers to Foyleside was "a massive positive for the centre and the city as a whole".
"Employing some 200 staff, this will replace the Debenhams with a new relevant retail offering to the centre together with a huge investment to refit the property which we hope will include the stores aspirational Flannels fashion hall."
Fergal Rafferty, Centre Manager, said the "significant investment will enhance the city centre retail offer as a whole and will reinforce Foyleside as the top regional shopping destination in the north west".
On 3rd December I wrote to Mike Ashley to ask that he consider the Debenhams site in Derry. Today's announcement is good for our city centre.— Colum Eastwood (@columeastwood) December 15, 2020
The Exec & Dept for the Economy must now work with industry & unions to develop a town centre development plan. https://t.co/cvNj6uSck0 pic.twitter.com/7tUesFFKJP
'Really positive news'
Foyle MP Colum Eastwood said he previously wrote to Mr Ashley about potentially taking over the site at Foyleside Shopping centre.
Mr Eastwood said: "I wrote to the CEO of House of Fraser, Mike Ashley, following the news of the collapse of Debenhams in Derry to ask that he consider taking over the Debenhams site in Foyleside".
"I am glad that the decision has been taken to acquire the site."
Derry and Strabane Mayor Brian Tierney welcomed the deal and said the timing of the announcement was "hugely important at what has been a very difficult time for the retail sector".