Ofir Akunis, Netanyahu's spokesman, said on Tuesday that the ministers, including Silvan Shalom, the foreign minister, will hand in their letters of resignation at Sunday's weekly cabinet meeting.
Sharon is expected to appoint new cabinet ministers from his centrist Kadima party to replace the outgoing Likud ministers.
Israeli radio reported that it was probable Shimon Peres would be appointed foreign minister.
Netanyahu was elected last month to head the Likud after Sharon quit the hard-line faction and formed a new centrist party.
Despite reported opposition from Likud cabinet ministers, Netanyahu followed through on Tuesday on a pledge to quit Sharon's government if elected to lead the Likud.
Sharon's appointments to the cabinet after the Likud ministers resign will give an idea of what a future Sharon-led government would look like.
Opinion polls forecast a landslide victory for the Kadima party.