Olson Co., the largest residential developer in San Gabriel, has sold part of the property that used to house the Wham-O toy factory and was later occupied by Sriracha maker Huy Fong Foods.

Earle Avenue Holdings, a limited liability company registered in Los Angeles in February, bought the vacant 77,000-square-foot industrial property at 4045 Earle Ave. from Olson for $5.5 million.

Lynn Knox of CBRE Group Inc. represented both the buyer and the seller in the sale, which closed March 31.

The buyer will use the site as a warehouse, Knox said.

Last year, Olson bought the 9-acre site from Huy Fong for $17.5 million, with the intention of building a residential complex on the site.

The large industrial building posed a development challenge: It was built across a channel, with one side of the property technically located in Rosemead and the other in San Gabriel. Olson subdivided the property, keeping the roughly 5-acre San Gabriel portion on which it is building an 88-unit townhome project. That project is set to open in May, said Scott Laurie, Olson’s chief executive.

Mark S. Gallatin, planning manager for the city of San Gabriel, said that the residential project signals positive change for the area.

“The Olson project is the largest residential project in San Gabriel in a generation and it’s an indication that there is a demand for new housing in the neighborhood,” Gallatin said.