Clothing firm Burberry has announced it will give the local community the Rhondda factory it is about to shut.
The company is to guarantee the value of the Rhondda plant
There has been a big campaign with celebrity backing to try to stop the company closing the 300-job Treorchy plant and moving production overseas.
Burberry said it would underwrite the factory's assets, effectively guaranteeing their value at £1m.
But unions said it was a "PR stunt," and local politicians said they would still campaign to keep the plant open.
The company said it was working with local and national groups "to ensure the best possible use of the assets and to leave a lasting legacy for the benefit of the community and future generations in the region."
Burberry said it was also "seeking to create a Wales-based committee to assist it locally to ensure the funds are used in the most beneficial and efficient way possible to those community members most affected".
It comes after a campaign which has seen personalities such as singer Sir Tom Jones, Manchester United manager Sir Alex Ferguson, and actors Ioan Gruffudd, Rhys Ifans and Emma Thompson voice support for the plant, which makes polo shirts.
In December workers travelled from south Wales to picket outside Burberry outlets in London, and they are due to stage another protest on Saturday.
Earlier this week Rhondda MP Chris Bryant called in the Commons for the firm to lose its Royal Warrant if it goes ahead with the plan to close the plant in March.
Workers travelled to London to picket Burberry stores there
Burberry chief financial officer Stacey Cartwright said it was "proud to announce this initiative today and we have been actively looking at how we could use the site to benefit the community".
She said: "Whether used or sold, the site amounts to a sizeable donation to Wales.
"Our primary concern has always been to assist employees in Treorchy who are affected by the closure, particularly with finding new employment, and we continue to do all we can to help."
In a joint statement, Mr Bryant and Rhondda AM Leighton Andrews said: "Clearly the campaign to save Burberry jobs in the Rhondda is having an effect.
"It's good news that Burberry seem to recognise that their miserly attitude to their workers and to the Rhondda is leaving a very bitter taste in the mouth.
But they said they would still be campaigning to keep the factory open and to "keep Burberry British".
Mervyn Burnett, GMB union organiser, said: "The community does not want an empty factory. It wants people in work.
Tom Jones is one of a host of celebrities fighting the closure
"Burberry's know full well that it would cost £250,000 to upgrade the electrics in the factory.
"GMB want to see Burberry to reverse their decision to close the Treorchy factory and maintain production of Burberry merchandise on the site," Mr Burnett added,
Welsh Secretary Peter Hain welcomed Burberry's "recognition of its debt and obligation to the community of Treorchy and the surrounding Rhondda Valleys".
But he said he needed to be satisfied that the factory and contents, valued at £1m by Burberry, are "in reality an asset, not a liability for the community in the current state".
"I remain implacably opposed to Burberry's decision to shut the Treorchy plant but am also conscious of the company's need to maintain its global reputation as a major British exporter in order to safeguard the 2,000 remaining Burberry jobs in the UK," added Mr Hain.
Assembly Enterprise Minister Andrew Davies said he had agreed to consider Burberry's donation proposal, but he had also made it very clear that "this gesture was wholly inadequate given the impact of the company's decision to vacate the Treorchy site".
"In addition the factory was built in the 1930s and as a pre-war building it is likely to require considerable investment to bring it up to a marketable standard," Mr Davies said.
Burberry has emphasised that it does not intend to abandon the UK and it has offered Welsh staff jobs at its Yorkshire plant.