CB Richard Ellis Group Inc. has been named nation’s largest brokerage by the National Real Estate Investor. This is the fourth consecutive year that the firm has finished at the top of the list.

The magazine’s list ranks the top 25 firms in the U.S., based on the aggregate value of sales and leasing transactions completed during the year.

According to the report, Los Angeles-based CB Richard Ellis was responsible for $225 billion of global sales and leasing transactions in 2006 more than the No. 2, No. 3 and No. 4 firms combined. The figures include the $2 billion acquisition of Trammell Crow Co. back in December.