The register
The register lists New Mountain Capital (U.K.) Ltd 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).
Companies House lists it as New Mountain Capital (U.K.) Ltd., number 10783891, incorporated 2017: 9 years of filings behind the name. The registered office is at 4th Floor, 16 Hanover Street Hanover Street, 4th Floor, London, W1S 1YD, W1S 1YD. By its SIC codes the business is in finance and insurance.
What the licence tells a candidate is that the door is not locked. Whether it is open this month is a question for New Mountain Capital (U.K.) Ltd's own careers page and the job boards, and the answer changes with the season and the order book.