Oakley continues to downsize its Orange County base, with a reduction in its staff expected as several key operations shift to join parent company Luxottica Group in Ohio, New York and Italy.

The company – founded 41 years ago by Jim Jannard and known for its sport sunglasses and goggles – has been steadily shrinking over the past year as Luxottica, based in Milan, prepares to integrate several Oakley divisions outside of California.

Luxottica, which bought Oakley for $2.1 billion in 2007, plans to move Oakley’s retail operation to its offices in Mason, Ohio, by the end of the year, the company said. The group’s New York office will manage all wholesale operations, and the Milan office will be in charge of marketing.

Oakley’s research and development, design, engineering and manufacturing departments will remain in Foothill Ranch, along with a number of administrative positions.

Oakley said Wednesday that 15-20 percent of its Foothill Ranch workforce would be affected. Afterward, the company will employ roughly 2,000 people in the county and at an Encinitas office.

“Last year, we announced the further integration of Oakley into Luxottica, allowing the brand to better leverage Luxottica’s resources, distribution channels, and manufacturing and market power,” a Luxottica spokesperson said in a statement. “This final stage of the integration will line Oakley up with the rest of Luxottica in terms of channels, functions and geographies, simplifying everything from decision-making to execution.”

Oakley’s apparel, footwear and accessories products will be “simplified,” the company said in the earnings call.

Sales have been struggling, the company stated, leading to a decrease in wholesale revenue of 1.6 percent in North America in the first half of the year compared with the same period a year ago.

Oakley in February laid off 76 people in Foothill Ranch. Last summer it cut 159 jobs there and eight in Encinitas, according to filings with the state.

The company also is closing its distribution operation in Ontario. A new distribution center will be built in Atlanta, Luxottica said.

Luxottica also owns Ray-Ban, Vogue Eyewear, Persol, Oliver Peoples and Alain Mikli and has licenses with Giorgio Armani, Burberry, Bulgari, Chanel, Dolce&Gabbana, Ralph Lauren, Tiffany & Co. and more.