Summit Commercial Properties and its parent Highridge Partners, both of El Segundo, sold the 900,000-square-foot Kaiser Center in Oakland to Swig Co. for a reported $200 million.

Terms of the transaction were not disclosed, although news reports estimated the sale between $190 million and $200 million. In a statement Thursday, the Swig Co. said the purchase price “is based on rents at or below market.”

The San Francisco-based private investment company acquired the 28-story Kaiser Center in a joint venture with Swig Investment Co. and GMAC Institutional Advisors. GMAC Commercial Mortgage, through its proprietary lending group, also provided $147 million in fixed-rate financing for the acquisition, Swig said in a statement Thursday. Swig will be the operating partner of the new venture.

Kaiser Center, which consists of three structures, was acquired for nearly $100 million by Summit Commercial Properties in 2003 from an ownership group that included a reorganizing Kaiser Aluminum. Summit then proceeded to invest an estimated $30 million in renovations. The building now boasts an occupancy rate of about 98 percent.

Tenants in the mixed-use center include the Bay Area Rapid Transit Authority, the University of California Regents, the Kaiser Foundation Health Plan and California Bank & Trust.

The Kaiser building obtained its name from industrialist Henry Kaiser, who constructed the building in 1960 and lived in its penthouse. Kaiser also founded Kaiser Permanente.