By THE ASSOCIATED PRESS

              BOGOTA, Colombia (AP) -- Carlos Castano, the leader of Colombia's top
              paramilitary militia, has resigned his post, the outlawed right-wing force said
              Wednesday, in a shake-up thought to reflect internal divisions.

              The 8,000-strong United Self-Defense Forces of Colombia, which has repeatedly
              massacred villagers it suspects of helping leftist rebels, has been targeted recently by
              government strikes. Some top paramilitary leaders have reportedly been calling for
              retaliation against the government, opposed by Castano.

              The militia, known by its Spanish initials AUC, said in a statement Wednesday that
              Castano had left the nine-member ruling command council and was reassigned to
              manage AUC's political affairs. The announcement ended days of speculation over
              Castano's future after a resignation letter was posted on a Web site last week.

              Despite the AUC's brutality, Castano has been a charismatic, media-savvy leader,
              capable of uniting diverse paramilitary factions under one umbrella. He is seen by
              some as a relative moderate within a group that includes more violent and ultra-right
              elements.

              Some fear that if he leaves the leadership of the AUC, the group could splinter into
              competing factions, heightening the violence and making any possible peace accord
              even more difficult.

              But in the announcement posted Wednesday on its Web site, the AUC tried to give
              assurances that the move did not mean retaliation against the government,
              underlining its ``will to respect the state and its institutions.''

              The AUC is a counter-guerrilla force formed by drug traffickers and landowners to
              combat rebel kidnappings and extortion.

              The group, which has operated with support from rogue members of Colombia's
              U.S.-backed military, was recently classified a terrorist organization by the U.S.
              government.

              During federal raids last month in Cordoba State, government agents searched the
              home of the wife of a top AUC commander and fatally shot the family's driver.

              The AUC protested the incident in its statement Wednesday, calling for an
              investigation, and saying the government must respect human rights in fighting the
              militias.