Korn/Ferry International Inc. (NYSE: KFY) ranked as the largest U.S. retained search firm with estimated 2010 U.S. retained search revenue of $353 million, according to the new list of largest retained search firms released by Staffing Industry Analysts.

Heidrick & Struggles International Inc. (NASD: HSII) ranked as the second-largest U.S. retained search firm with estimated U.S. retained search revenue of $238 million in 2010.

Seven firms generated at least $25 million in U.S. retained search revenue in 2010.

Corporate members of Staffing Industry Analysts can download the list of largest U.S. retained search firms by clicking here.

Lists of largest direct hire firms and outplacement firms have also been released.

Robert Half International Inc. (NYSE: RHI) is the largest U.S. provider of direct hire with 2010 U.S. revenue of $159 million in this segment. Adecco SA ranked second with $83 million in U.S. direct hire revenue in 2010. Overall, seven firms posted at least $25 million in U.S. direct hire revenue in 2010.

Corporate members of Staffing Industry Analysts can download the list of largest U.S. direct hire providers by clicking here.

Among outplacement firms, Right Management ranked as the largest with U.S. outplacement revenue of $375 million in 2010. Only three firms generated at least $50 million in U.S. outplacement revenue in 2010.

Corporate members of Staffing Industry Analysts can download the list of largest U.S. outplacement providers by clicking here.