Bukhari 2525

Narrated Ibn `Umar: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