The official said Silvan Shalom, who over a long career served as foreign minister and in other senior positions, was appointed Sunday.
Netanyahu would remain the ultimate decision-maker on negotiations if they resume. The official spoke on condition of anonymity because he was not authorized to brief the press on the announcement.
Shalom was recently named interior minister in Netanyahu's new government, sworn in last week. The coalition is dominated by nationalist and religious parties, setting it on a collision course with the international community.