JERUSALEM — A report commissioned by the government of Prime Minister Ariel Sharon yesterday accused various Israeli agencies of complicity in the building of unauthorized Jewish settlement outposts in the West Bank.

The outposts, dozens of tiny satellite communities meant to expand the reach of existing settlements, are supposed to have been removed under the U.S.-supported peace plan known as the "road map." But the Sharon government has lagged doing so, with the tacit understanding of the Bush administration.

Settlement outposts have long been a sore point between the two sides.

Although often little more than a cluster of trailers and water towers clinging to bare West Bank hillsides, the outposts stake a symbolic claim to land the Palestinians want for their future state.

The long-awaited report by Talia Sasson, a former state prosecutor, said Israel's housing ministry, immigration agency and military provided money, logistical support and infrastructure for more than 100 unauthorized outposts, which usually are erected by militant settlers.

"It appears that blatant violations of the law have become institutional and institutionalized and that no enforcement of the law is seriously intended," said the report, which was presented to Sharon yesterday.

Excerpts appeared in editions of the daily newspaper Maariv.

Army troops occasionally have been deployed to remove such outposts, usually sparking brawls with radical young settlers, but structures almost always reappear within days.

Many Israelis regard the scenes of settlers wrestling, cursing and spitting at soldiers sent to evacuate them as an uneasy precursor of the government's planned evacuation of settlements in the Gaza Strip this summer.

The Sasson report cited official practices such as providing electricity, roads and military protection for the settlement outposts, some of them set up on land owned by Palestinians.