Loeb works with technology hedge-fund employees, including an Asia-based analyst, Henry King, who is also under investigation, according to another source briefed on the case.

The sources declined to be identified because the matter is not public.

A spokesman for Goldman declined to comment on insider-trading probes and on the current employment status of Loeb and King. Neither Loeb nor King responded to emails seeking comment.

According to a regulatory filing and court records, employees of Goldman Sachs, Wall Street's most influential firm, have been pulled into the insider-trading case of a former board member, Rajat Gupta, who is preparing for trial on criminal and civil charges.

No one at Goldman has been accused of any wrongdoing.

Gupta, a former director of Goldman Sachs and Procter & Gamble Co, and a former global head of the McKinsey & Co consultancy, is to go on trial in May. He has denied charges that he tipped now-convicted Galleon Group hedge fund founder Raj Rajaratnam with Goldman and Procter & Gamble board secrets.

In an annual 10-K filing with the U.S. Securities and Exchange Commission on Tuesday, Goldman included an item "Insider Trading Investigations" that did not appear in regulatory filings a year ago or at the end of the third quarter. A 10-K gives a comprehensive summary of a public company's performance and includes issues that are material to securities investors.

"From time to time, the firm and its employees are the subject of or otherwise involved in regulatory investigations relating to insider trading, the potential misuse of material nonpublic information and the effectiveness of the firm's insider trading controls and information barriers," the filing said.

"It is the firm's practice to fully cooperate with any such investigations."

A spokeswoman for the office of the Manhattan U.S. Attorney, the prosecutor in a broad insider-trading probe of hedge funds in recent years, declined to comment. The U.S. Department of Justice says that out of 64 people charged in the crackdown dubbed "Perfect Hedge", 59 have either been convicted or pleaded guilty.

The Wall Street Journal first reported the inquiries about Loeb and King.

Loeb's name came up during proceedings in Manhattan federal court last November as a potential witness in the Gupta case. Others who could be deposed included Goldman Chief Executive Officer Lloyd Blankfein, Chief Financial Officer David Viniar and President and Chief Operating Officer Gary Cohn, according to court records.

Rajat Gupta's lawyer, Gary Naftalis, declined to comment on Wednesday, but in court he has asked prosecutors to share any information on possible Goldman inside sources that Rajaratnam and Galleon had.

"This is hot stuff for us," Naftalis told U.S. District Judge Jed Rakoff at a January 20 hearing, according to a court transcript.

The lawyer said that if there were other people at Goldman or Procter & Gamble who provided Galleon with inside information about those companies or their clients "they constitute real exculpatory information" for the defense.

Rajaratnam, whose technology-focused hedge fund had $7 billion under management at its peak, was convicted last May and is serving an 11-year prison term, the longest ever imposed for insider-trading offenses. A judge also ordered Rajaratnam to pay $92.8 million to the SEC.

(Additional reporting by Matthew Goldstein; Editing by Martha Graybow and Tim Dobbyn)

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