Katherine Jackson’s battle to prevent a major sale of Michael Jackson’s music catalog ended in Los Angeles when a judge ruled her appeal “lacked merit.”

The decision upholds a plan to sell half of the late pop icon’s extensive collection to Sony Music Group, an agreement reportedly valued at $600 million.

In recent years, the Jackson family matriarch has tirelessly opposed the sale.

Katherine argued that the deal between the co-executors of Michael Jackson’s estate—John Branca and John McClain—and Sony violated the terms of the singer’s will and trust.

Despite her efforts, the court maintained that the executors were within their legal rights, noting the will grants them broad discretionary power.

“The will gave the executors broad powers of sale, with no exception for the specific assets at issue in this case,” read the court filing which People first reported. “As such, the probate court did not err in concluding that it was Michael’s intent to allow the executors to sell any estate assets, including those at issue in the proposed transaction.”

The judge also dismissed Katherine’s attempt to block the transaction, stating she had “forfeited” her argument by failing to raise her objections in a lower probate court.

Attempts to reach Katherine’s legal team for comment have been unsuccessful.

At 94, Katherine remains a lifetime beneficiary of a sub-trust from The Michael Jackson Family Trust, established after Michael died in 2009.

The trust also benefits Michael’s three children—Prince, 27, Paris, 26, and Bigi, 22—and various unnamed charities.

Michael Jackson’s estate generates approximately $75 million annually.

Earlier this year, Sony finalized a deal to acquire half of Michael’s publishing and recording masters for around $600 million.

This ruling clarifies the scope of the executors’ powers under Jackson’s will and illustrates the ongoing complexities of managing high-profile celebrity estates.