The U.S. Securities and Exchange Commission has dropped its insider trading investigation of Matthew Korenberg, a former Goldman Sachs & Co. managing director accused of tipping a Galleon Group employee about a corporate merger.

The decision followed a series of presentations to SEC lawyers by Korenberg’s defense team, led by John Hueston of Irell & Manella. Irell announced the end of the five-year probe in a press release on Wednesday.