If anyone emancipates his share ina slave and has enough money to pay the full price for him, a fair price for the slave should be fixed, his partners given their shares, and the slave be thus emancipated, otherwise he is emancipated only to the extent of the first man's share.  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ أَعْتَقَ شِرْكًا لَهُ فِي عَبْدٍ فَكَانَ لَهُ مَالٌ يَبْلُغُ ثَمَنَ الْعَبْدِ قُوِّمَ عَلَيْهِ قِيمَةَ الْعَدْلِ فَأُعْطِيَ شُرَكَاؤُهُ حِصَصَهُمْ وَعَتَقَ عَلَيْهِ الْعَبْدُ وَإِلاَّ فَقَدْ عَتَقَ مِنْهُ مَا عَتَقَ  

This hadith has been reported on the authority of Ibn 'Umar through another chain of transmitters.  

عَنْ نَافِعٍ