GREEN BAY, Wis. — Shopko Stores Operating Co. began liquidating its assets last month after it was unable to find a buyer for its struggling retail business.

The retailer, which filed for Chapter 11 bankruptcy protection in January, was still seeking to auction off its optical business as this article went to press.

“This is not the outcome that we had hoped for when we started our restructuring efforts,” said chief executive officer Russ Steinhorst. “We want to thank all of our teammates for their hard work and dedication during their time at Shopko.”

In February Shopko announced plans to close 250 stores, but the company was still hoping to sell off its remaining 120 stores as a viable ongoing business. But Shopko was unable to find a buyer, and the company wound up canceling an auction that had been planned.

Instead, it enlisted the firm Gordon Brothers to oversee a liquidation process that began in late March. The last remaining Shopko stores are expected to close by mid-June.

Shopko operated in 24 Midwestern and Western states.

The retailer opened its first discount store here in 1962.

Founded by Chicago pharmacist James Ruben, Shopko was part of a wave of discount department store banners that were launched that year.

The first Walmart, Kmart and Target stores also debuted in 1962.