The former Artis Capital Management analyst told U.S. Magistrate Judge James Francis in Manhattan that he received tips from David Riley, a former chief information officer at Foundry Networks Inc, including one about the company's pending $3 billion (1.79 billion pounds) takeover in 2008 by Brocade Communications Systems Inc.

Teeple, 42, pleaded guilty to one count of conspiracy to commit securities fraud. He also agreed to forfeit $553,890, according to his plea agreement.

"I deeply regret the role that I played in this illegal conduct," he told the judge.

Federal prosecutors announced criminal charges against Riley, 48, Teeple and John Johnson, 47, in March 2013, saying that subsequent trades on the information led to more than $27 million of improper gains.

Johnson was the former chief investment officer of the Wyoming Retirement System, which he joined in 2010, after the government's allegations. Johnson made more than $136,000 on trades based on information Teeple leaked to him about the Foundry takeover, prosecutors said.

Johnson pleaded guilty last year to one count each of securities fraud and conspiracy. Riley pleaded not guilty and is scheduled to go on trial in July. Johnson has not yet been sentenced. A related civil case the U.S. Securities and Exchange Commission brought against the three men is pending.

On Wednesday, Teeple told the judge that Riley tipped him off to the approximate value of the Brocade deal and about when it would be announced. Teeple said he knew that Riley was violating his duty of trust and confidence to Foundry when he disclosed the inside information.

Teeple, of San Clemente, California, faces a maximum of five years in prison.

Artis, based in San Francisco, did not immediately return requests for comment. The firm said last year that it was cooperating with the investigation.

(Reporting by Bernard Vaughan; Editing by David Gregorio, Sofina Mirza-Reid and Nick Zieminski)

By Bernard Vaughan