Britain’s Tate museum group has officially named the recently opened extension of Tate Modern after Len Blavatnik, the billionaire industrialist whose Access Industries has branched out into music, film and television.

The new Blavatnik Building has been named in recognition of the donation from Blavatnik’s family foundation, which pledged a reported £50 million ($65 million) gift to the Tate in 2011. Blavatnik said the Tate provided an “incomparable service to the arts, culture and education throughout the world,” and that his family were honored to support Tate and be linked to the new building.

“The generosity of this gift is almost unprecedented in Tate’s history,” Tate director Nicholas Serota said. “The transformation and extension of Tate Modern was hugely ambitious and relied on many people to bring it to fruition, but Len Blavatnik’s enthusiastic support ensured the successful realization of the project and I am delighted that the new building now bears his name.”

The building was initially named Switch House, after the part of the former power station that stood on the site.

Blavatnik, who was born in the Soviet Union, built his company into a huge conglomerate that now owns numerous entertainment properties, including Warner Music Group, Deezer, AI Film and Access Entertainment. After emigrating to the U.S. in 1978 he became a U.S. citizen in 1984 and subsequently a British citizen in 2010. His foundation has funded numerous arts projects and exhibitions in Britain.

The new Tate Modern building was designed by architects Herzog and de Meuron, and opened to the public on June 17 last year. It received grants from the government and donations from private individuals, trusts and foundations.

The new space has already received more than six million visitors since opening.