TAMPA - Two of the best known commercial real estate companies in Tampa soon will be under one roof.

CB Richard Ellis Group Inc., based in El Segundo, Calif., said Tuesday that it's buying Trammell Crow Co., a rival company based in Dallas, for $1.8 billion. The deal must be approved by Trammell Crow shareholders.

Both companies have a significant presence in Tampa: CB Richard Ellis leases and manages some of the area's top office buildings, including Bank of America Plaza and 100 North Tampa. Trammell Crow has had a hand in some of the area's most notable development projects, including the Marriott Waterside Hotel and the Port Ybor industrial park.

The two companies have a lot in common: Both handle leasing and management for landlords, represent tenants looking for new space, and provide a host of commercial real estate services for corporate clients. One significant difference: Trammell Crow is a developer, and CB Richard Ellis is not.

Ray Sandelli, CB Richard Ellis' senior managing director for Florida, said he was told of the acquisition late Monday night. It's too early to speculate on what the combined Tampa operations will look like, or whether any workers may be laid off, he said.

"It's not like we're going to jam this thing together and displace people," said Sandelli, who works out of the Tampa office. It will take up to eight weeks to review the operations of both companies and make personnel and organizational decisions, he said.

CB Richard Ellis employs about 100 people in Tampa. Sandelli said he didn't know how many people worked in Trammell Crow's Tampa office. Bob Abberger, Trammell Crow's managing director, couldn't be reached for comment.

Trammell Crow will retain its name and remain operating as CB Richard Ellis' development subsidiary, Sandelli said.

Nationally, the deal would create a commercial real estate services company with about $4.4 billion in annual revenue, more than 10 percent of the commercial real estate market.

With nearly 50 offices in the United States, Trammell Crow employs about 6,200 workers and posted 2005 earnings of $59.4 million on $896 million in sales.

CB Richard Ellis employs about 14,500 workers and posted 2005 net income of $217.3 million on sales of $2.91 billion.

Information from The Associated Press was used in this report. Reporter Dave Simanoff can be reached at (813) 259-7762 or dsimanoff@tampatrib.com.