'McKinsey Mafia'

McKinsey grew to 9,000 employees from 500 in the 35 years he spent there. Even by 1995, his second year at the helm, its global sway was such that a Sunday Times headline complained of a "McKinsey mafia." In the past year, the newspaper said then, one firm veteran had taken over the prime minister's policy unit, another became the youngest member of the cabinet and a third became deputy governor of the Bank of England, leaving the helm of the Confederation of British Industry. He was replaced there by a McKinsey veteran.

In 2001, Gupta founded a business school in Hyderabad, India, called the Indian School of Business, whose board was stocked with that country's corporate leaders, along with McKinsey director Anil Kumar, who has pleaded guilty to providing Rajaratnam, 53, with inside information.

Investing Partners

Rajaratnam and Gupta have a 13-year history of business collaboration and co-investing. As of May, Rajaratnam had a stake in a fund managed by New Silk Route NSR Partners LLC, co- founded by Gupta. At a January 2007 benefit honoring Rajaratnam called "A Night for India," Gupta was the honorary chair along with Zubin Mehta, who conducted the New York Philharmonic in an Elgar cello concerto and Bruckner symphony, according to a program. The music played after a black-tie dinner and before a champagne reception.

Gupta's reach has extended beyond India, where he was born in the Communist-run Eastern city Kolkata. After McKinsey, he joined the boards of Russia's OAO Sberbank, American Airlines parent AMR Corp., Harman International Industries Inc. and the business outsourcing company Genpact Ltd. Last year, Sberbank announced that Gupta, its highest-paid director, would instead become a "strategic adviser." He has also served as the UN Secretary General's special adviser on management reform, and in July became chairman of the International Chamber of Commerce. His vice chairman, Stephen Green, another McKinsey alumnus, was the chairman of HSBC Holdings Plc. He left HSBC and ICC to become the U.K. trade minister.

'Classy Guy'

Bala Balachandran, who has known Gupta for three decades and was on the founding faculty of the Indian School of Business, sees his old colleague as "a classy guy" who "delivered results as the number one guy at McKinsey."

Balachandran, who left that school to found the Great Lakes Institute of Management in Chennai, India, in 2004, said Gupta's post-McKinsey world of investments was different.

"The arrogance became so high" among sophisticated investors, he said in a May 2010 interview.