California's attorney general accused scores of insurance companies of conspiring to leave the state simultaneously after voters approved a rollback in rates. But he decided not to file charges.

"We found that on the most basic decision - whether to compete at all - insurance companies were consulting one another, seeking and providing reassurance that they would follow one another in lockstep," Attorney General John Van de Kamp said in a report issued Wednesday after a two-year investigation.The report had looked into the behavior of insurance companies after voters in 1988 approved Proposition 103, which rolled back property, auto and other insurance rates to 20 percent below 1987 levels.

The attorney general decided not to bring civil or criminal charges against the companies, saying that the withdrawal was short-lived, that it would be hard to prove damages, and that his office had other business to tend to.