Nearly 300 jobs are under threat in Swansea at a call centre outsourcing company.
Conduit UK said it had lost a major client which had undertaken a "strategic consolidation of suppliers".
The firm said work for 290 will end in October unless it finds new clients.
Chief executive Denis Creighton said: "Whilst we are hugely disappointed to lose a key client, our main focus is on ensuring that we support our staff during this difficult period."