'Abd Allah b. 'Umar reported the Messenger of Allah (ﷺ) as saying:If anyone emancipates his share in slave, a fair price for the slave should be fixed, give his partners their shares, and the slave be thus emancipated. Otherwise he is emancipated to the extent of the share which he emancipated.
حَدَّثَنَا الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَنْ أَعْتَقَ شِرْكًا لَهُ فِي مَمْلُوكٍ أُقِيمَ عَلَيْهِ قِيمَةَ الْعَدْلِ فَأَعْطَى شُرَكَاءَهُ حِصَصَهُمْ وَأُعْتِقَ عَلَيْهِ الْعَبْدُ وَإِلاَّ فَقَدْ عَتَقَ مِنْهُ مَا عَتَقَ " . .
AbuDaud
The Book of Manumission of Slaves • Hadith 3940