Non-profit Regent’s said membership would mean it is better placed to ensure its interests are represented.
Its membership was approved last month by the board of UUK, the organisation that acts as the voice of universities and represents them in talks with the government.
The only other private member of UUK is the non-profit University of Buckingham, which joined UUK’s predecessor organisation, the Committee of Vice-Chancellors and Principals.
For-profit institutions BPP University and the University of Law are other potential candidates that could seek to join UUK.
Aldwyn Cooper, Regent’s vice-chancellor, said: “We are pleased to have met the stringent new criteria set out by UUK and to be the first applicant to attain this standard.”
He added: “UUK makes a significant contribution to higher education policy and does excellent work in representing the sector at home and abroad. As a member, we will be better placed to influence sector discussions and ensure our interests are represented.
“We particularly look forward to working with UUK’s members and sharing our unique and internationally focused perspective.”
Professor Cooper continued: “We also intend to maintain our close working relations and memberships of GuildHE and London Higher whose activities we also value.”