A Manhattan federal judge has ruled that Apple Inc. cannot force arbitration in a proposed class action accusing the tech giant of concealing a flaw in its operating system that gave third parties unauthorized access to customers’ private communications.

U.S. District Judge Lorna G. Schofield of the Southern District of New York, in her ruling, rejected Apple’s bid to require arbitration, where costs to a proposed class representative could be higher and Apple could have a say in selecting judges tasked with entering final rulings.