It is narrated from Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "If a slave is jointly owned between two partners, and one of them frees his share, if the one who frees is wealthy, then the highest or fair price will be set, which is neither less nor more, and then the share will be taken from him with wealth."
Hadith Referenceمسند الإمام الشافعي / كتاب العتق والولاء والمدبر والمكاتب وحسن الملكة / 1071
Hadith Takhrijاخرجه البخاري العتق ، باب اذا اعتق عبدا بين اثنين أو امة بين الشركاء (2521) ومسلم، الايمان، باب من أعتق شركا له فى عبد (1501 - بعد 1667)۔