Salesforce.com plans to expand its Chicago branch to 1,000 employees, a leap that would make it one of Chicago's largest tech companies. While it's unclear how many employees the cloud computing company currently has in its River North office, a spokeswoman at World Business Chicago says there are more than 500. Salesforce's Chicago expansion began in 2011 when it acquired Model Metrics and its 150 employees. CEO Marc Benioff says the city's exploding tech scene and ability to attract skilled workers played a role in the decision to further expansion, reports Crain's. No word on whether the company has plans to relocate to accommodate its growth, but the 116k SF lease it holds at River North has been sufficient so far. The expansion puts Salesforce in elite company, as only Groupon, Motorola Mobility and Nokia/Navteq have more than 1,000 employees in Chicago. Salesforce reported $5.4B in revenue, and employs more than 16,000 worldwide. [CCB]