Israel is handing over greater responsibility for security in four West Bank cities, including Bethlehem and Ramallah, to Palestinian forces, BBC reported.
But Israeli officials say their troops would still go into the four cities when they think it necessary.
They would also continue to maintain control of roads outside them.
The move seems aimed at boosting the position of the Palestinian President Mahmoud Abbas, who controls the West Bank, correspondents say.
But a senior Palestinian official dismissed it as a sham, and called for an end to all Israeli incursions, the Reuters news agency reported.
Israel will partially withdraw from Qalqilya, Bethlehem, Jericho and Ramallah as well.
Israeli forces would continue to operate in the West Bank "in order to thwart terrorist operations", the Associated Press reported Israeli officials as saying.
Israel has occupied the West Bank, including East Jerusalem, since 1967, settling more than 450,000 Jews in the area.