LONDON—Willis Group Holdings P.L.C. reported revenues of $3.34 billion for 2010, up 2.5% over the prior year.

The London-based brokerage said Wednesday that commissions and fees grew 3% in 2010 from 2009, and that organic growth in commissions and fees was up 4% last year over 2009.

Willis’ net income for 2010 was $455 million in 2010, up nearly 4.4% over the prior year.

“We had a great 2010, with another year of strong organic growth and operating margin expansion,” Joe Plumeri, Willis’ chairman and CEO, said in a statement accompanying the results.