The register
The register lists Sisecam UK PLC in London as a licensed sponsor on Skilled Worker, an entry that goes back to at least 2026. Rating on the current register: Worker (A rating).
At Companies House the business is Sisecam UK PLC (company number 15253757), a public limited company incorporated in 2023, 3 years ago. Registered office: 18 King William Street, London, EC4N 7BP, EC4N 7BP. Its filed activity puts it in business services. It has traded under other names before, including Sisecam UK Limited.
Holding a licence is the expensive, slow part done. For Sisecam UK PLC the question each time is only whether the role and the pay fit the current rules, and that is checked per vacancy.