On the same day that a jury convicted hedge fund manager Raj Rajaratnam, federal prosecutors notched another victory when a former account manager at a semiconductor company, Manosha Karunatilaka, pleaded guilty to charges of insider trading.

Appearing on Wednesday in Manhattan federal court, Karunatilaka admitted that he fed confidential tips about Taiwan Semiconductor Manufacturing Co <2330.TW>to Primary Global Research, a so-called expert network that provides information to investors.

Karunatilaka admitted to receiving more than $35,000 from Primary Global for providing inside information between January 2008 and June 2010, prosecutors said.

Manosha Karunatilaka thought he could moonlight for an expert networking firm and sell out his employer in the process, U.S. Attorney Preet Bharara said in a statement.

Under his plea agreement, Karunatilaka faces three to four years in prison for conspiracy to commit securities fraud and wire fraud. He is scheduled to be sentenced in September.

It was not clear whether the Rajaratnam conviction announced earlier on Wednesday had any bearing on Karunatilaka's guilty plea. His lawyer did not immediately return a call for comment.

Karunatilaka is one of dozens of people swept up in a massive federal investigation of insider trading that has shaken Wall Street in the past year and led to arrests of hedge fund managers, analysts and others.

Several people tied to California-based Primary Global have also been indicted in recent months, including other part-time consultants and a hedge fund manager who allegedly traded on insider information obtained from the firm.

The case is: USA v. Shimoon et al, U.S. District Court for the Southern District of New York, No. 1:10-mj-02823.

(Reporting by Jeff Roberts; Editing by Lisa Shumaker)