حَدَّثَنَا إِبْرَاهِيمُ بْنُ مُوسَى الرَّازِيُّ، أَخْبَرَنَا عِيسَى بْنُ يُونُسَ، حَدَّثَنَا عُبَيْدُ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَنْ أَعْتَقَ شِرْكًا مِنْ مَمْلُوكٍ لَهُ فَعَلَيْهِ عِتْقُهُ كُلُّهُ إِنْ كَانَ لَهُ مَا يَبْلُغُ ثَمَنَهُ وَإِنْ لَمْ يَكُنْ لَهُ مَالٌ عَتَقَ نَصِيبُهُ ‏"‏ ‏.‏

Ibn 'Umar reported the Messenger of Allah (PBUH) as saying: If anyone emancipates his share in a slave, he should emancipate him completely if he has enough money to pay the full price ; but if he has none, he will be emancipated to the extent of his share. Translation Not Available

Book Ref: Sunan Abi Dawud Book 31 Hadith 3943
Web Ref:  Sunan Abi Dawud Book 30 Hadith 3932