NEW YORK, Oct 19 (Reuters) - IBM IBM.N placed senior executive Robert Moffat on leave of absence after he was arrested in the largest ever hedge fund insider-trading scheme.

Moffat, senior vice president and head of International Business Machines Corp.’s systems and technology group, is being charged with passing on insider information to a hedge fund. He had been working for IBM since 1978.

“In view of a U.S. federal investigation into his personal activities, Mr. Moffat has been placed on temporarily leave of absence and is no longer serving as an officer of IBM,” said company spokesman Edward Barbini.

Moffat is accused of passing on information on IBM itself ahead of the company's quarterly results, as well as those of Sun Microsystems JAVA.O while IBM was looking at its books for a possible acquisition. The FBI said Moffat was one of the IBM executives conducting due diligence on Sun.

He has also been charged with giving insider information on Advanced Micro Devices Inc AMD.N, obtained through IBM's business negotiations with the company.

IBM named Rodney Adkins as acting head of the systems and technology group. Adkins will also oversee development and manufacturing, the company said.

The insider trading scandal centers on Galleon Group founder Raj Rajaratnam. Executives at leading chipmaker Intel Corp INTC.O and management consulting firm McKinsey & Co. were also implicated. (Reporting by Ritsuko Ando; Editing by Derek Caney)