More than 100 workers from the building contractors, the Cuddy Group, have been offered jobs by a house building firm amid speculation about its future.
Persimmon Homes said it was offering jobs to staff after Cuddy gave "formal notice of its intention to appoint receivers", putting jobs at risk.
Staff at Cuddy's Llandarcy plant in Neath told BBC Wales they have been told to report to the office on Monday.
The Cuddy Group has been approached for comment.
Earlier on Friday, Carmarthenshire council said work had stopped at the former Pontrilas factory in Llanelli, which Cuddy were demolishing
David Jenkins, the council's board member for resources, said no decision would be made about the building until it was "fully informed of the Cuddy situation".
The Neath-based company has been profitable in recent years and is well known as a sponsor of Welsh sports clubs, most notably the Ospreys, where owner Mike Cuddy was chief executive until 2012.
Previous jobs it has worked on include the demolition of Cardiff City football stadium Ninian Park, knocking down the former Oceana nightclub building in Swansea as well as removing asbestos at Bronglais Hospital in Aberystwyth.