BERKELEY -- Grocery Outlet will move its longtime Berkeley headquarters to Emeryville, the latest sign of the discount grocery chain's rapid expansion.

The retailer plans to move its headquarters from Fifth Street in Berkeley, which has been home for about two decades, to an office building at 5650 Hollis St. in Emeryville, which currently houses pharmaceutical company Bayer, said Marc Drasin, vice president of real estate for Grocery Outlet. More than 125 employees will move to the new office by early spring 2014, and within four years, the company will occupy the entire 54,000-square-foot building, Drasin said.

Grocery Outlet, a full-service grocer that sells band-name groceries for as much as 50 percent less than conventional supermarkets, is in the midst of a growth spurt, adding dozens of new stores every year. Last month, Grocery Outlet opened a store in Richmond, bringing the third full-service grocery store to the city. Founded in San Francisco in 1946, the retailer now has almost 200 stores.

Contact Heather Somerville at 925-977-8418. Follow her at Twitter.com/heathersomervil.