The Prophet ﷺ said, "He who manumits his share of a slave and has money sufficient to free the remaining portion of that slave's price (justly estimated) then he should manumit him (by giving the rest of his price to the other co-owners)." Nafiʿ added, "Otherwise the slave is partially free." Aiyub is not sure whether the last statement was said by Nafiʿ or it was a part of the Hadith.
عَنِ النَّبِيِّ ﷺ قَالَ مَنْ أَعْتَقَ نَصِيبًا لَهُ فِي مَمْلُوكٍ أَوْ شِرْكًا لَهُ فِي عَبْدٍ وَكَانَ لَهُ مِنَ الْمَالِ مَا يَبْلُغُ قِيمَتَهُ بِقِيمَةِ الْعَدْلِ فَهْوَ عَتِيقٌ قَالَ نَافِعٌ وَإِلاَّ فَقَدْ عَتَقَ مِنْهُ مَا عَتَقَ قَالَ أَيُّوبُ لاَ أَدْرِي أَشَىْءٌ قَالَهُ نَافِعٌ أَوْ شَىْءٌ فِي الْحَدِيثِ