The new Twitter headquarters will be at Market Square, an historic building located in the Central Market area of San Francisco, the company on Friday. Twitter expects to move into the approximately 1-million-square-foot building at 1355 Market St. in the middle of 2012.

Twitter was founded in San Francisco and is currently based in the city's South of Market neighborhood. On Tuesday, in a bid to keep Twitter from moving away as it outgrew its headquarters, the San Francisco Board of Supervisors passed a six-year payroll expense tax exclusion for companies moving into the Central Market and Tenderloin area. The city hopes the presence of Twitter will help to create an "innovation cluster" in the area, located in the middle of the city, which suffers from high vacancies and blight. The tax exclusion passed by a vote of 8 to 3.

"We are proud that Twitter will be among the first companies moving into the Central Market area and will be playing a role in its renewal with the city and with other businesses, arts organizations, and the numerous community organizations that have been doing hard work in the neighborhood for many years," Twitter said in the blog entry. Three-quarters of Twitter employees who live in San Francisco are involved with causes and charities in the city, the company said.

The IDG News Service