Another large office portfolio has hit the market. Real estate services firm Divco West recently announced plans to sell their 4 million sq. ft. portfolio of West Coast properties. The offering should fetch upwards of $1 billion. Only two of the properties are located outside of California.

Included in the sale are two major office towers: San Francisco’s 555 and 575 Market Street. Divco bought the buildings in 2003 from Tishman Speyer for $79.5 million. The property was 80% vacant at the time, but Divco has leased much of that space over the past few years. The property is now roughly 10% vacant, according to the company.

If September was any indication, Divco has chosen an opportune time to sell. Last month, for example, two major San Francisco office towers were sold for a combined $105 million. Beacon Capital Partners bought 100 California St. for $98 million. Westbrook Partners owned the 273,000 sq. ft. office property. The other sale was 33 New Montgomery St., another San Francisco office building that fetched $75 million in September.

Divco West owns the properties through its equity fund, Page Mill Properties LP. Page Mill's investors include the California Public Employees' Retirement System and the California State Teachers' Retirement System, which contributed a combined $200 million into the fund.