A former director of a global management consulting firm has pleaded guilty to securities fraud charges, admitting making $2.6 million by feeding inside stock information to one of America's richest men.

Anil Kumar of Santa Clara, Calif., entered the plea Thursday in federal court in Manhattan. Kumar is a former director at McKinsey & Co. Inc.

He agreed to cooperate in the government's case against billionaire hedge fund operator Raj Rajaratnam. Rajaratnam has pleaded not guilty to charges that he earned at least $36 million from illegal trades based on insider information.

Kumar agreed to forfeit $2.6 million. Prosecutors say Rajaratnam paid him $1.7 million to $2 million since 2003 to feed him secret information about McKinsey's clients.