Sayyiduna Ibn Umar (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) said: "Whoever frees his share in a slave and has with him the amount of the slave's price, a fair value shall be fixed, the partners shall be given their shares and the slave shall be free; otherwise, only as much shall be freed as has been freed?" He said: "Yes."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العتق / 21352