Three employees at public companies and an executive of an expert-networking firm on Thursday became the latest to be charged in a wide-ranging Wall Street insider trading probe.

James Fleishman, 41, of Santa Clara, Calif., the networking executive, was charged with wire fraud and conspiracy for providing confidential information to the firm’s clients, including hedge funds, U.S. Attorney Preet Bharara said.

Others charged were Mark Anthony Longoria, 44, of Round Rock, Texas; Walter Shimoon, 39, of San Diego; and Manosha Karunatilaka, 37, of Marlborough, Mass. They were charged with wire fraud and conspiracy to commit securities fraud and wire fraud, according to papers filed in federal court in Manhattan.

It was not immediately clear who would represent the defendants at initial court appearances.

Prosecutors also announced that Daniel Devore, formerly a global supply manager for Dell Inc. who worked as a consultant for the firm, pleaded guilty Dec. 10 to wire fraud and conspiracy charges.

The charges came several weeks after a New Jersey consulting firm executive became the first to be arrested in the investigation.

The new federal insider trading probe targets industry analysts, experts and consultants.