Net widens in US insider-trading probe

NEW YORK: Federal investigators are gearing up to file charges against a wider array of insider-trading networks, some linked to the criminal case against billionaire hedge-fund manager Raj Rajaratnam that shook Wall Street last week, people familiar with the matter said.

The pending crackdown, based on at least two years of investigation, targets securities professionals including hedge- fund managers, lawyers and other Wall Street players, the people said, declining to be identified because the cases aren't public. Some probes, like the one that focused on Rajaratnam, rely on wiretaps. Others stem from a secret Securities and Exchange Commission data-mining project set up to pinpoint clusters of people who make similar well-timed stock investments.

Investigators have struggled for years to build cases against large institutional investors such as hedge fund managers, who often deflect regulatory queries about suspiciously timed bets, arguing they're statistical flukes amid their millions of trades. The case against Rajaratnam, built on recorded conversations within a web of alleged conspirators, offers a glimpse of how US investigators are using more aggressive tactics to cut through the blizzard of trading and trace the flow of information.