The Michael Jackson Company won a major legal battle this week … because a judge has ordered a civil case — centered around alleged sex trafficking — be handled out of court and in a private setting

Remember … Frank Cascio and his siblings — former family friends of the late pop star — are suing his estate for more than $200 million, alleging they were victims of child sex trafficking by Jackson in the 1980s.

The siblings previously came to a settlement agreement with the Jackson estate … and, as part of that settlement, the judge found Cascio and company signed off on handling disputes like this in private arbitration, as opposed to the public court system.

The Cascios have been engaged in legal turmoil with Jackson’s estate for a long time … even flying into Los Angeles to attend a hearing in January.