It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever frees his share in a jointly owned slave, and he has wealth enough to reach the slave's price, a fair value will be assessed against him; he will give his partners their shares, and the slave will be freed at his expense. Otherwise, as much of him is freed as has been freed."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الغصب / 11520