Los Angeles-based Oakwood Worldwide said on Tuesday it will sell 30 apartment buildings to Archstone-Smith Trust for $1.4 billion, including its flagship 1,151-unit Oakwood Toluca Hills property.

The transaction includes 10,000 apartment units, more than 40 percent of them in Southern California, Archstone-Smith said in a press release. Oakwood, a manager and owner of corporate housing and furnished apartments, will continue to manage about half of the units being sold, and retain a portfolio of 20,000 managed corporate housing and furnished units worldwide.

The deal will boost Archstone-Smith’s Southern California assets to 22 percent of its portfolio from 19 percent. Closing is expected to occur in stages beginning in April.

Also included in the sale are the 883-unit Oakwood Woodland Hills East in Woodland Hills, the 597-unit Oakwood Marina del Rey and the 549-unit Oakwood Long Beach Marina in Seal Beach. There are also smaller buildings in Pasadena, Thousand Oaks and La Jolla.

Other Oakwood properties being sold are located in the Washington, D.C., area, the San Francisco Bay Area and a number of smaller properties in Boston, Chicago and near Seattle.

In recent years, Englewood, Colo.-based Archstone-Smith has been aggressively acquiring properties throughout the L.A. region, particularly on the Westside. The publicly traded real estate investment trust is the nation’s third largest apartment owner with 250 complexes that altogether contain 90,000 units.

Oakwood was founded in 1960 by Howard F. Ruby, Ed Broida and Bob Franks and remains a privately held company.