Sahih al-Bukhari Book 49, Hadith 10
That the Prophet (ﷺ) said, "Whoever frees his portion of a (common) slave."
That he used to give his verdict regarding the male or female slaves owned by more than one master, one of whom may manumit his share of the slave. Ibn `Umar used to say in such a case, "The manumitted should manumit the slave completely if he has sufficient money to pay the rest of the price of that slave (which is to be justly estimated) and the other shareholders are to take the price of their shares and the slave is freed (released from slavery)." Ibn `Umar narrated this verdict from the Prophet.
The Prophet (ﷺ) said, "Whoever frees his portion of a common slave should free the slave completely by paying the rest of his price from his money if he has enough money; otherwise the price of the slave is to be estimated and the slave is to be helped to work without hardship till he pays the rest of his price."