Sports Direct has agreed to buy House of Fraser for stg£90m (€78.4m) in cash.
It was earlier reported that Sports Direct founder Mike Ashley was close to an agreement to buy the struggling British retailer.
In a statement to the London Stock Exchange, Sports Direct said it had acquired 169-year-old department store chain, saving "around 17,000 jobs."
The sports clothing and equipment retailer already owned an 11% stake in the brand.
House of Fraser appointed Ernst & Young (EY) as administrators earlier after failing to reach agreement with its main creditors.
A general view of a House of Fraser store in London | Image: Clive Gee/PA Wire/PA Images
Back in June, 31 of the retailer's 59 stores across the UK were earmarked for potential closure.
But the Dundrum Town Centre store was set to survive.
A spokesperson said the Dublin branch was not up for possible closure, as it is held under a separate legal entity.
Mandate trade union represents Irish House of Fraser workers.
Their spokesman is Gerry Light: "All I can say is that we're increasingly concerned.
"We were aware for a while now that the House of Fraser business was in difficulty.
"We have written to the Irish management, asking them to indicate the potential impact that might arise for our members."