Tim Cowden, a veteran office broker, and office specialist Linda Greenberg have joined Colliers International as senior vice presidents, along with former G&E industrial broker Rich Montgomery and office specialist John Shelton.

Most of Grubb & Ellis' top brokers have now left for such firms as BRE Commercial/NAI, CB Richard Ellis, Colliers, Burnham Real Estate Services and Voit Commercial. Grubb & Ellis was once one of the city's leading brokerages, boasting up to 70 brokers covering all areas of the county.

Colliers recently opened a new Downtown office in the Merrill Lynch Building to complement existing offices in University Towne Centre, Carlsbad and Temecula.

Cowden, an office leasing and sales specialist, has closed deals at such signature Downtown properties as Symphony Towers and One America Plaza and the Washington Mutual Tower.

Grubb & Ellis' 12,000-sf office in the Eastgate Mall area now has a crew of less than a half dozen as veteran brokers have signed up with other firms in droves. Over the last few weeks, some 10 Grubb & Ellis employers went to work for BRE Commercial.

Reg Kobzi and Joe Greeno joined CB Richard Ellis. David O'Rell, Grubb & Ellis' research director, took a job with Xceligent, a commercial multiple listing service.