Hector Ruiz will step down as chairman of chip maker Globalfoundries, following reports linking the former Advanced Micro Devices chief executive to the largest insider trading scheme in decades.

Ruiz will immediately take a voluntary leave of absence and will be resigning from the company January 4, Globalfoundries said in a statement on Monday.

The statement, which said Ruiz submitted his resignation in September, did not state a reason for his decision.

Alan Lanny Ross, former chief executive of Broadcom Corp , will serve on an interim basis until a p

ermanent chairman has been appointed.

Ruiz was said to have passed on confidential information regarding AMD's spin-off of Globalfoundries to a hedge fund manager when he was AMD's CEO.

Shares of AMD, which owns a large but minority stake in the venture with Abu Dhabi investors, rose about 2.3 percent in premarket trading on Monday.