Prime Minister Stanislav Gross won the Czech Social Democrat party chairmanship on Saturday, keeping his post as head of a three-party coalition cabinet. The vote is a setback for Gross's coalition partner, the centrist Christian Democrats, who have been demanding that the Social Democrats replace Gross as cabinet chief due to a row over his family finances. The Christian Democrats may leave the cabinet, forcing Gross into a minority rule. --SP 2139 Local Time 1839 GMT