Sandeep Aggarwal, 40, entered the plea to conspiracy and securities fraud charges, telling U.S. Magistrate Judge Ronald L. Ellis that he passed along tips he learned from a former colleague at Microsoft Corp. about plans the company had to create a search engine advertising partnership with Yahoo Inc.
The plea settled charges brought against Aggarwal when he was arrested in July in San Jose, Calif.
Aggarwal said he was working as a senior analyst at the San Francisco office of research firm Collins Stewart when he provided inside information "to improve my standing as an analyst" and to boost the company's revenues. Collins Stewart has since been acquired by the Vancouver-based Canaccord Financial Inc.
He choked up as he told the judge: "I knew what I was doing was wrong, and I am extremely sorry for my actions."
His cooperation deal with the government could bring him substantial leniency for charges that otherwise would carry a potential prison sentence of up to 25 years. A tentative sentencing date was set for May 14.
During his plea, Aggarwal admitted providing tips to Richard Lee, a former SAC portfolio manager who pleaded guilty in July and is cooperating with law enforcement.
In wiretap evidence described in a criminal complaint, Aggarwal is heard telling Lee that he had spoken to "a senior guy at Microsoft" who had been "very, very accurate in the past in terms of ... telling me what's going on."
The plea came just hours before SAC Capital was scheduled to plead guilty in Manhattan federal court to insider trading charges in a deal that carries with it a $1.8 billion penalty, described by the government as the largest insider trading penalty in history.
The company is owned by billionaire Steven A. Cohen. He has not been criminally charged.