The sentence, one of the longest ever in an insider-trading case, was lighter than the 19-and-a-half-year minimum prison term that prosecutors had sought, but is still above the 10 years handed down recently in another major insider trading case. Federal inmates typically must serve at least 85 per cent of their terms before being eligible for release.
It was not immediately clear if Rajaratnam would be ordered to prison immediately or allowed to remain under house arrest while he appeals his conviction. Prosecutors and defense lawyers were still discussing sentencing matters in court after the judge announced the intended prison term.
The Galleon Group fund founder, 54, made no statement on his behalf before the sentence was pronounced by U.S. District Judge Richard Holwell at a court hearing in Manhattan. The judge also ordered him to pay a $10 million fine.
Rajaratnam was convicted of 14 securities fraud and conspiracy charges in May after a two-month trial.
Prosecutors had made Rajaratnam the central figure of a sprawling criminal case, unveiled in October 2009, that touched some of America's top companies, including Goldman Sachs Group Inc, Intel Corp, IBM and the elite McKinsey & Co consultancy.
"There's no one who's Mr. Rajaratnam's equal in terms of the length and breadth of his insider trading crimes," Assistant U.S. Attorney Reed Brodsky told the court, urging for the maximum punishment.
Prosecutors called Rajaratnam the "modern face" of insider trading, putting him in a dubious pantheon of Wall Street power players such as takeover specialist Ivan Boesky and junk bond financier Michael Milken, principal figures in a mid-1980s insider-trading case. Both men served about two years in prison.