NEW YORK (Reuters) - A disgraced former McKinsey & Co partner testified that hedge fund manager Raj Rajaratnam paid him a $1 million “bonus” for tipping him about an acquisition by chip-maker Advanced Micro Devices Inc, a client of the consulting firm.Anil Kumar told jurors yesterday that he supplied confidential details about AMD’s 2006 purchase of graphics chip-maker ATI Technologies to Rajaratnam, who is on trial on criminal charges of running a vast insider trading network.“He called me at home and he said, ‘I just wanted to thank you. That was fantastic, we are all cheering you at the office right now’,” Kumar testified in Manhattan federal court. “That made me very nervous. I was worried if there was a lot of champagne flowing in the office.”Sri Lankan-born Rajaratnam, 53, is accused of making $45 million in illicit profit between 2003 and March 2009. The case is the biggest Wall Street insider trading case since speculator Ivan Boesky and junk bond financier Michael Milken were prosecuted in the mid-1980s.Rajaratnam, founder of the Galleon Group hedge fund and once named one of the richest people in the US by Forbes magazine, has pleaded not guilty and vowed to clear his name. The prosecution wants to show the jury that Rajaratnam received inside tips supplied by high-ranking friends in corporate America. His friends included Kumar and Rajiv Goel, a former Intel Corp treasury group executive who like Kumar has also pleaded guilty and agreed to testify for the government.Indian-born Kumar, 52, began his testimony last Thursday. He has yet to be cross-examined by Rajaratnam’s defence team.Kumar said he “nearly fell off my chair” when Rajaratnam paid him $1 million for information on AMD’s $5.4 billion buyout of ATI. The deal was announced in July 2006 and completed three months later. Rajaratnam made more than $20 million on his trades, according to the government.The case has embarrassed McKinsey, an elite management consultancy. At its annual partner meeting in Washington this week, global managing director Dominic Barton is expected to speak with partners about the trial and the separate civil charges against former McKinsey top executive Rajat Gupta, the Financial Times reported. McKinsey itself has not been charged with any wrongdoing.Kumar also described how at one point Rajaratnam mailed him confidential documents about product plans of Intel, the main competitor to AMD.“I was terrified at having such documents in my office. It was clearly inappropriate,” he testified. “I asked my assistant to shred it.”Kumar said Rajaratnam did not tell him in advance that he was sending the documents on Intel, or where he got them.Nineteen out of 26 people charged in the Galleon case have pleaded guilty, a probe marked by the wide-scale use of phone taps. Digital recordings of Rajaratnam’s conversations with Kumar, Goel and a former Galleon employee Adam Smith were played to the jury last Thursday.