It is narrated from Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (ﷺ) said: "Whoever frees his share in a jointly owned slave, and he has enough wealth equal to the value of the slave, then the slave's value should be assessed justly. All the partners should be given the price of their shares (from his wealth), and the slave should be freed on his behalf. Otherwise, whatever portion of the slave has been freed, is freed."
Hadith Referenceمسند الإمام الشافعي / كتاب العتق والولاء والمدبر والمكاتب وحسن الملكة / 1070
Hadith Takhrijاخرجه البخارى العتق باب اذا اعتق عبدًا بين اثنين أو امة بين الشركاء (2522)، 2523- ومسلم، العتق ، باب من اعتق شر كاله في عبد (1501)۔