Last July, Variety broke the news that EMI Music Publishing would be going on the block, and a Bloomberg report today says that Sony has held preliminary talks to acquire a majority stake in the company, citing unnamed people with knowledge of the matter. Abu Dhabi-based Mubadala Investment company, which holds a majority share of an estimated 60% of  the company, is said to be seeking some $4 billion for that stake.

Sony/ATV administers the catalog and its chairman, Martin Bandier, led a consortium (also including Mubadala, Jynwel Capital, the Blackstone Group’s GSO Capital Partners and David Geffen) that acquired the company in 2012, which saw Sony acquiring around 40% of the company. Mubadala has begun exploring the sale of the catalog, which features some 2.1 million songs, including titles by Carole King, Motown classics, and standards like “Somewhere Over the Rainbow,” according to the report. While the report also says Mubadala is exercising an option that would force Sony to acquire its stake or trigger a sale of the entire company, a source close to the situation clarified that it could also sell its stake to another party, which would then become the majority owner. While the process cannot officially begin until the end of June, Mubadala has already begun reaching out to potential suitors.

Sony/ATV is already the world’s largest music publisher and has been No. 1 in market share in every quarter except one over the past five years, falling second to Warner/Chappell during one quarter in 2017.

Len Blavatnik, whose Access Industries owns Warner Music Group, is said to be one of the interested parties.

Reps for Sony and Mubadala either declined or did not immediately respond to Variety’s requests for comment.

As streaming has returned financial vitality to the music business the value of copyrights has risen, as evidence by the value of Mubadala’s asking price — EMI sold for $2.1 billion in 2012. Earlier this year the Songs Publishing catalog, a relatively new company that publishes The Weeknd, Lorde, Diplo and other contemporary songwriters but lacks a deep catalog like EMI’s, which is almost unparalleled, sold to Kobalt for an estimated $150 million.